Spanish and Nahuatl Views on Smallpox and Demographic Catastrophe in the Conquest of Mexico:

Robert McCaa
version: March 14, 1994, excludes notes and bibliography
©Portions appearing in Journal of Interdisciplinary History, 25:3 (Winter 1995), 397-431.

Controversy over the demographic consequences of conquest and colonization quickened with the five-hundredth anniversary of European intrusion into the Americas. A recent revisionist article in this journal by Francis J. Brooks concludes that the first Old World epidemic introduced into Central Mexico, that of 1520, was "a mild attack of smallpox, such as occurred in contemporary Europe with some suffering, some deaths, and little further effect." From a cross-checking of five key sources the author concludes that "reporting that many died of it [smallpox] must be the influence of the Franciscan myth." "Nothing in the historical record allows us to feel confident that one-third to one-half of the Aztec population died of smallpox in 1520. No such catastrophe actually occurred." If smallpox did not contribute to demographic collapse in Central Mexico in 1520, then the "catastrophe" school of contact population history is in error. If the best documented case of a "virgin soil" epidemic is wrong, the extension of the paradigm to other first encounters between Europeans and Native Americans becomes tenuous, if not untenable.

The history of the first case of smallpox in Central Mexico is vital to understanding the effects of Spanish conquest and colonization of the region and beyond. Historians and archaeologists have expended enormous energy to establish the demographic record of native peoples in Central Mexico. For historians, this region is also the most-easily documented case of population decline with many eyewitness accounts, extensive tax records for a large number of native villages and towns, many inquiries by secular and religious authorities, and chronicles by both conquerors and the conquered.

As an outsider with no stake in either the revisionist or the "High Counters" camp, I was intrigued by the radical implications of Brooks' thesis and began perusing his sources. Soon, I was lured into a rapidly escalating cross-examination of all seemingly relevant, readily available contemporary texts on the subject. Because the critique rests mainly on narratives rather than numerical evidence, I studied a wide-ranging body of sixteenth-century documents including annals, genealogies of rulers, reports, chronicles and histories. I re-examined the five sources used by Brooks--accounts by Hernando Cortés, Francisco López de Gómara, Bernal Díaz del Castillo, and the Franciscans Toribio de Motolinía and Bernardino de Sahagún--and all other published sources in Spanish and Nahuatl which seemed relevant (Table 1). I moved from a guarded sympathy for the revisionist argument, to the discovery of misread sources, flawed reasoning and false analogies, and finally to disagreement with fundamental points of the paper. I agree with the revisionist argument that an overall mortality figure of one-half for the 1520 epidemic is too high, but this figure was discounted long ago by the principal writers on this subject. Moreover, the only source for this fraction, the Historia de los indios de la Nueva España (completed after 1541), is a mutilated, bastardized text attributed to, but not authored by, Fray Toribio de Motolinía, as will be shown below.

Unlike Brooks, I am confident that the impact of smallpox in New Spain was several times greater than in Europe. The alleged similarity is not corroborated by the very considerable mass of evidence which has been published on this subject over the past 470 years. For the pre-statistical era, precise estimates of smallpox mortality are unattainable for large regions of the world. Rather than quibble over whether the fraction of natives dying from smallpox was one-fifth, one-fourth, or one-third, I canvass the sixteenth-century texts for epidemiological and demographic insights. In the end, I favor the middle ground--somewhere substantially higher than what was common to sixteenth-century Europe, but lower than the crude figure of one-half attributed to Motolinía--closer to what the Franciscan actually wrote: "that in some provinces half the people died, and in others a little less;" in contrast to the statement in the Historia: "in most provinces more than half died, and in others a little less."

Early Accounts of Smallpox.

Brooks argues that the story of smallpox devastation originates in "Motolinía's" Historia, that this is the "basis (to say no more)" of subsequent descriptions of high smallpox mortality, such as those by López de Gómara and Bernal Díaz. In Table 1, references are listed by approximate year of composition and their principal sources identified--eye-witness reports, annals, chronicles and histories. Revisionist skepticism warns against the ready acceptance of later chronicles or histories. Yet we are faced with the reality that over the sixteenth-century many native records were destroyed by Christian authorities in campaigns to eradicate vestiges of indigenous religion. For Spanish writers, on the other hand, there were few opportunities to publish, indeed the important works by Cortés, López de Gómara, and Sahagún were suppressed for years, although not destroyed. While book publishing began in Mexico in the 1530s, reaching over 200 titles by the end of the century, publication in New Spain or even Spain was an expensive and uncertain proposition. Some manuscripts on the conquest went through several copyings and enjoyed surprisingly wide circulation without being published. Others were copied by successive generations of local scribes, and earlier versions have since disappeared. Authors reworked, revised, and re-copied, as new sources or interpretations appeared. Bernal Díaz' two versions of the Historia Verdadera is a well-known example. The earliest copy was sent to Spain in 1576, but he continued to revise a second copy in Guatemala until his death in 1584. The first was printed in a bastardized edition almost a half century after his death (1632); the second was not published until 1904. Representative of the annals genre is the Anales de Tlatelolco, two copies of which survive. The first was probably written in the 1540s and the second in the late seventeenth or early eighteenth-century, but both purport to incorporate pictographs and texts created much earlier. The writings of the great Franciscan authors Toribio de Motolinía and Bernardino de Sahagún suffered similar travails. The Historia attributed to Motolinía was a hurried copy of his Memoriales (portions of which have since been lost) made, probably in Spain, by a copy-editor-publicist who lacked training in Nahuatl and also lacked Motolinía's zeal for accuracy.

Before turning to the complicated story of the mutilation of Motolinía's work, I consider the beginnings of smallpox in Central Mexico at Cempoala (near Veracruz) and then examine the death of the Mexica ruler Cuitlahuactzin a few months later. At issue is the course of smallpox in a nine-month period from April 1520, when Pánfilo de Narváez landed an expeditionary force near Veracruz, to January 1521, when Cortés returned to the Central Valley of Mexico to prepare the assault on the Aztec capital, Tenochtitlán.

The earliest Spanish recording of smallpox in Central Mexico, dated August 30, 1520, is a report to the emperor Charles V by Licenciado Lucas Vázquez de Ayllón, judge of the Real Audiencia of Santo Domingo. This report, first published in 1866, has gone unnoted by most historians, although not by Angel Rosenblat, a self-proclaimed "moderate" in the debate over Indian population trends after contact. Judge Vázquez de Ayllón, writing only a few months after the event, described a voyage with the Narváez flotilla to Cozumel, an island off the east coast of the Yucatán peninsula, and then to Veracruz. On Cozumel he found very few natives and attributed their disappearance to smallpox. According to the Judge, the natives had been "stuck" (pegado) by the disease introduced by Indians from the island of Fernandina (Cuba) who were brought to Cozumel as auxiliaries in the company of Spaniards. Vázquez de Ayllón had no theory of contagion but his report shows that he understood how the pasty mucous of smallpox spread (pegado as in pegante, originally, fish-paste).

Shortly, the Narváez expedition introduced smallpox to Veracruz. After a tropical storm destroyed a half-dozen ships and scattered the remainder, the flotilla regrouped a few weeks later, near Veracruz and the native settlement of Cempoala. Almost immediately, smallpox broke out on the mainland. Vázquez de Ayllón reports that great harm had been inflicted on those lands [New Spain] ("en aquellas tierras han hecho mucho daño") because smallpox had stuck the Indians there ("porque han pegado las viruelas a los indios dellas"). Elsewhere he writes that the Narváez expedition included many natives from Fernandina ("se llevaban en la dicha armada mucha cantidad de los indios de la dicha isla"), "the reservoir of pestilence in the New World," according to Crosby. The report states unequivocally that smallpox was carried from Fernandina to the mainland by natives in the Narváez expedition. Unfortunately for the historical record, by mid-May Pánfilo de Narváez rebelled against the Judge (who by this time had fallen ill also), forced him and his party onto a ship and sent them back to Cuba to be deposited in the hands of Narváez' sponsor, Diego Velasquez. Thanks to political intrigue and a second storm, the ship was carried instead to a remote corner of Hispaniola. Vázquez de Aylon disembarked, trekked across the entire island on foot, and arrived safely at Santo Domingo where he wrote his lengthy account of the affair for the emperor.

Thus ends this eye-witness report on events within the Narváez camp, several weeks before the well-known confrontation with Cortés and before any large-scale effects of the introduction of smallpox could be observed. The smallpox story receives only a few lines in Judge Vázquez de Ayllón's report. Yet, the fact that disease is mentioned at all in a record detailing mutiny, subversion, and possibly the loss of a valuable colony hints at the significance of the eruption of pestilence in "those lands". The epidemic is important to the story because it reveals the recklessness of Velasquez' mutiny and his utter disregard for the prosperity both of Fernandina and of the new lands. The severity of what Judge Vázquez de Ayllón saw with respect to smallpox is limited to the brief phrase "han hecho mucho daño" (has caused great harm), but its significance required no elaboration for the emperor's advisors or others familiar with the demographic catastrophe unfolding in the islands.

The introduction of smallpox among the Aztecs is frequently attributed to a Black slave (by name, Francisco Eguía, according to one account). Hallowed by repetition, this motif becomes something of a trope--unlike the almost ignored story of "Joan Garrido," also a Black slave, the first to sow and harvest wheat in Mexico. The tale of the smallpox-infected slave occurs in most Spanish chronicles of the conquest (those by Motolinía, López de Gómara, and Díaz del Castillo--but not Cortés or Sahagún), in native-mestizo accounts such as the Relación Geográfica for Tlaxcala by Diego Muñoz Camargo, the Codex Ramírez, Alva Ixtlilxochitl's Décima Tercia Relación and even in many modern textbook descriptions of the conquest of Mexico. According to Brooks, reciting this anecdote undermines the credibility of all would-be chroniclers of smallpox in two ways. First, it reveals their dependence on Motolinía, the first-known written account of the story, and, second, "Motolinía's" own Historia is fable, an exercise in "mythopoesis," a strained allegory for the Biblical account of the Ten Plagues. Brooks reasons that Motolinía needed an "Ethiopian" and that without a theory of contagion, no Spaniard would have made the connection much less remembered a source for the disease.

Whether smallpox was introduced by a Black slave, by Cuban Indians, or by both is important only for determining the validity of sources. All historians, including Brooks, agree that smallpox reached Central Mexico for the first time in April or May 1520, with the arrival of the Narváez expedition. As to the theory of contagion, the Spanish vernacular had long provided a simple, but credible notion of how the disease was spread--in a word, "pegar" (stick or adhere)--as will be explained below.

From May to September, smallpox spread slowly inland, 150 miles to Tepeaca and Tlaxcala, and then on to Tenochtitlán in September or October. A second eyewitness account of smallpox is reported in another letter to Charles V, that by Hernando Cortés dated May 15, 1522, ten months after the fall of Tenochtitlán. Cortés, seeking to justify his transgressions and to position himself to claim vast rewards from the newly conquered lands, provides an exceedingly detailed report of his actions. He describes the high regard which native leaders had for him and thereby justifies his usurpation of royal authority in appointing native rulers. Cortés writes that "many chieftains were dying and they wished that by my hand and with your approval and mine others be put in their place." The many deaths of leaders were due to "the smallpox distemper which also enveloped those of these lands like those of the islands." I emphasize what Brooks' paraphrase omits: Cortés' explicit comparison of the impact in New Spain with what had happened in the islands.

While the guessing about how many natives peopled the islands before 1492 (ranging for Hispaniola from 8 million to as few as 60,000) continues without relief, there is widespread agreement that depredation and disease drove the native population to near extinction by 1520. Within a decade of first contact, Spaniards turned to raiding nearby islands for slaves, the favored method for replenishing the labor supply. The near-demise of natives on the islands was used to justify Cortés' expedition of 1519. His license was not to conquer or settle "those lands," but to "acquire knowledge and measure the said land, and to bring captive Indians from there, from which they could serve on the island of Cuba to prospect for gold and the other things for which they are needed...." Cortés chose instead to conquer, and his letters to the emperor were designed to justify his disobedience as a means of assuring his reward.

In an earlier letter to the emperor dated October 30, 1520, Cortés does not comment on smallpox or his appointing chieftains to leadership. It is likely that deaths of smallpox-infected chieftains had occurred by that date, but Cortés was simply biding his time until the wisdom of his usurpations could be made clear to the emperor. Cortés' letters, regardless of length, were not histories, but rather briefs, written to advance his cause in the eyes of Charles V. The relevance of smallpox was to warrant Cortés' actions. Otherwise disease is scarcely mentioned in his letters. Of some 250 pages which Cortés addressed to the emperor from 1520 to 1526, the smallpox story is disposed of in a half-page.

Cortés names only one leader who died of smallpox, the Tlaxcalan Maxixcatzin. In 1519, Maxixcatzin was the first highland ruler to embrace Cortés' cause, and then, following the Noche Triste (June 30, 1520), the first to provide succor to the badly beaten cristianos. In the ensuing weeks, when the Mexica sought to press their victory by rallying all the native kingdoms against the invaders, Maxixcatzin spoke forcefully and persuasively for Tlaxcalans to remain loyal to Cortés. Fortunately for Cortés, Maxixcatzin's death from smallpox occurred after the loyalty of his people had been assured, but the precise date is unrecorded.

Cuitlahuactzin and Other Native Rulers Died of Smallpox. Although Brooks flatly denies it, the Mexica ruler Cuitlahuactzin also died of smallpox, as did many other native rulers, allies and enemies alike. Within a pair of parentheses, Brooks would consign to the historian's dustbin the standard story of the death of the Mexica hero: "...Cuitlahuac, who died (of smallpox, say many historians without evidence; of unspecified causes, say the sources that report his death) either sixty or eighty days later, the end of August or of September." No primary sources are cited, nor is there a name for even one of the "many historians". The most authoritative indigenous source, the Annals of Tenochtitlán, chronicles Cuitlahuatzin's death as follows: "The tenth ruler was installed in Ochpaniztli, Cuitlahuatzin. He ruled for only eighty days; he died at the end of Quecholli of the pustules (smallpox), when the Castilians had gone to Tlaxcala." This would place the death in the month of "Quecholli," which in 1520 fell in late November or early December (not August or September as Brooks would have it), scarcely a month before Cortés renewed the assault on the Mexican stronghold, Tenochtitlán.

Some confusion about Cuitlahuatzin's death may arise because Cortés did not report the event. Indeed, Cortés' letters scarcely acknowledge the name of his most formidable opponent. On the night of June 30, the Noche Triste, when Cortés' troop fought their way out of Tenochtitlán, Cuitlahuactzin's forces nearly annihilated the castellanos and their Tlaxcalan auxiliaries. López de Gómara cites Cuitlahuactzin's military and diplomatic successes in rallying the natives and also reports the death as occurring from smallpox, before Christmas 1520. Bernal Díaz remembered Cuitlahuactzin as "the lord who ejected us from Mexico" and attributes his death to smallpox also occurring before Christmas. Motolinía cannot be the source for these accounts because the Franciscan chronicler, like Cortés, does not mention Cuitlahuactzin. In Spain Cuitlahuactzin's death is first chronicled by Peter Martyr, in the Fifth Decade of his De Orbe Novo written before his own death in 1526. Martyr reported that Cuitlahuactzin (incorrectly referred to as "Hastapalappa", the name of the place he last ruled) "had been named king at Temistitan [Tenochtitlán], but after a reign of four months had died of smallpox and had been succeeded by his sister's son, Catamazin [Cuauhtémoc]." Martyr does not reveal his sources, but he is not following any of Cortés' extant Cartas.

Sixteenth-century native annals tell the same story: "Upon the death of Mutezuma those of Mexico made Cuitlavazi from Estapalapa, brother of Mutezuma, their leader. He was lord for eighty days: smallpox was given to all the Indians and many died, before they [the Castilians] returned to conquer the city." The Crónica Mexicayotl, written down in 1609, interprets "Quecholli" as December 3 and notes as well the death of Cuitlahuactzin's little son Axayacatzin, also from smallpox ("totomonalliztli"). Sahagún's personal history of the conquest, completed in 1585, confirms these accounts and tersely weighs the military significance of the epidemic: "Among the Mexicans who fell victim to this pestilence was the lord Cuitlahuactzin, who they had elected a little earlier. Many leaders, many veteran soldiers, and valiant men who were their defense in time of war, also died." The meticulous nineteenth-century Mexican historian Manuel Orozco y Berra ascribes Cuitlahuactzin's death to smallpox, dated near November 25th.

The Nahuatl sources which report cause of death agree that Cuitlahuactzin succumbed to an unusual, terrible pestilence--reported variously as cocoliztli (illness, great plague or pestilence, smallpox), huey zahuatl (great pestilence of smallpox, great ulcerous leprosy), or totomonaliztli (blisters, smallpox). These generic terms describe visible symptoms. A precise translation is impossible because there was nothing like smallpox in the Nahuatl lexicon. Barlow interprets "totomonaliztli" as "calenturas" (fevers) where Lockhart favors "pustules". A sixteenth-century "mexicana-castellana" dictionary defines the root term "totomonaltia" as "hazer a otro bexigas o ampollas" (to make blisters or pustules [of smallpox] under the skin of another). The Aubin Codex (Annals of Tenochtitlán) record Cuitlahuactzin's reign and death. The accompanying pictograph shows his enshrouded corpse encircled with tiny globes (ampollas), the symbol for smallpox according to Orozco y Berra. Chimalpahin, the historian of Chalco, also attributes the death to "pustules and ulcers from smallpox" (ampollas y llagas de viruelas [çahuatl]).

The epidemic of 1520 enveloped other towns in Central Mexico and ravaged the ruling clans, weakening their diplomatic and military cadres. Chimalpahin informs us of the smallpox-inflicted deaths of some of the lords of Chalco, using the word "çahuatl" four times in a brief passage. A Nahuatl-French edition of Chimalpahin's Séptima Relación first published a century ago, invariably translates "çahuatl" as "variole" (smallpox). Chimalpahin reports:

Year 2-flint, 1520. Then there was the plague [çahuatl] which caused great mortality. From it died the Huehue Yotzintli Tlayllótlac Teuhctli, Señor of Tzacualtitlan Tenanco Amaquemecan. He ruled thirty-three years.

And from this same thing died his adviser.... Also of smallpox [çahuatl] died Señora Tlacocihuatzin.... From the same cause died Itzcahuatzin y Tlatquic, from Itzcahuacan, who succeeded in governing thirty-five years and his own son, the said Necuametzin [also died of smallpox]....

Bernal Díaz attests as well that the lord of Chalco died of smallpox, but López de Gómara only notes the death without stating the cause. Cortés scarcely mentions the Chalco incident, and Motolinía ignores it entirely. The absence of comments by Cortés or Motolinía is insignificant because there is ample independent evidence of smallpox striking down many of the native elite.

Other Nahuatl sources relate the epidemic in a single sentence, such as the Anales de Tlatelolco, where some 4,000 words are allotted to the conquest but only two lines to the epidemic: "Then a plague [cocoliztli] broke out of coughing, fever, and pox [çahuatl]. When the plague [cocoliztli] lessened somewhat, (the Spaniards) came back..." In Cuauhtitlan, the entry for 1520 reads: "Then Yohualtonatiuh was inaugurated. It was in his time that the Spaniards arrived. Both Citlalcoatl and Yohualtonatiuh died of the smallpox." Outside the central basin and 50 miles southeast of Puebla in the district of Tepeaca, the surviving copy of the Annals of Tecamachalco, which dates from the 1590s, chronicles the event-of-the-year for 1520 as "very frightful great smallpox" ("cenca temahmauhti ynic mo chiuh huey zahuatl"--"muy espantoso para se hizo gran viruela"). This chronicle omits any mention of conquest or deaths due to war. Smallpox was the event for 1520.

The better test would be to tally all the Nahuatl annals by whether smallpox is or is not mentioned for 1520. In the meantime, from this survey of native annals and pictographs, the widespread occurrence of references to the epidemic and its devastation of the native elite is impressive.

The military significance of the pestilence should be underscored as well. Upon accession Mexica rulers quickly sought to establish hegemony and legitimacy by raiding subject towns. With the sudden death of Cuitlahuatzin and the assent of the youthful Cuauhtémoc, there was no opportunity to impose allegiance through war. Instead, Cortés proceeded to pick off subject-towns, often through diplomacy, one-by-one. An authoritative military history contends that ultimately

Cortés' victory was more political than military, disrupting Aztec allegiances through the death of two kings and augmenting his own meager forces with tens of thousands of native troops while undercutting the Aztecs. With the fall of Tenochtitlán, the rest of Mesoamerica fell to Spanish domination with little or no struggle.

Motolinía and Other Contemporary Sources.

Brooks questions the veracity of supposed eye-witness accounts of the epidemic claiming that they are derived from a "Franciscan myth," a history authored by Friar Toribio de Motolinía and tailored to fit Biblical prophecy. Brooks sees "Motolinía's" Historia as the keystone in the argument that smallpox devastated Mexico in 1520. The commonalties among the texts are seen as weakening their credibility, but common threads may strengthen the fabric, re-enforcing agreement on key themes. Brooks would have López de Gómara copying from the Historia and, in turn, Bernal Díaz from López de Gómara, yet their descriptions differ, as shown in Table 2). López de Gómara repeatedly acknowledges his dependence upon Motolinía--a fact long recognized by Mexicanists--but Cortés' secretary also used a variety of other sources some of which are no longer available. In turn, Bernal Díaz' "True History" was written, in part, to correct the excesses of López de Gómara's "Conquistas de Cortés." I was surprised to discover that while Motolinía reports only one anecdote regarding smallpox, López de Gómara recounts three, and Bernal Díaz five.

Motolinía's uniqueness lies in his use of Biblical allegory and the observation that natives did not know how to deal with smallpox. López de Gómara, unlike other chroniclers, describes pox as striking (pegó) a single house in "Zempóalam" (implied, but not stated in Motolinía) and then spreading "from one Indian to another and because the Indians were many and slept and ate together, spreading widely and quickly, killing as it went throughout that land"--other details which went unreported by Motolinía. Bernal Díaz was present in Cempoala before the smallpox attack had subsided. He relates its spread in terms of "striking and filling all the land with it [smallpox]", "from which there was great carnage and according to what the Indians said they had never had this illness before." These authors agree on the severity of the attack, except that Díaz mentions smallpox in five distinct episodes compared with only three in López de Gómara.

Any assertion that Díaz never saw smallpox in Mexico is probably false. Díaz arrived in Cempoala in May 1520 and was present later in Tlaxcala, when Cortés was appointing leaders to replace those felled by the disease. For January 1521 Díaz remarks that, upon beginning the final campaign against Tenochtitlán, he and his companions re-entered Texcoco, a suburb of the Aztec capital, without opposition, in part due to the fact that many warriors were still recovering from smallpox and were too weak to fight as a result of the illness which hit and spread throughout the land. Abridged English translations of the Historia Verdadera often omit this and other episodes where smallpox is mentioned.

Brooks insists that Motolinía's account of the spread of illness comes from Biblical notions of the clean and the unclean, but it is telling that Motolinía and most sixteenth-century Spanish writers, secular as well as religious, uniformly rely on the word "pegar" (to hit, spread, or stick) to convey, somewhat metaphorically, the means of transmission of smallpox. The word is used to describe the spread of matlazahuatl (typhus), plague, and other diseases which are now considered contagious. Pegar also describes how fire is spread and the means by which one gets vices, customs, opinions, knowledge, and even jokes. Thanks to the word "pegar," by the seventeenth-century, as the theory of communicable disease became respectable among educated Europeans, Spanish folk discourse required little adjustment to explain the transmission of contagious diseases ("Vale tambien comunicar una cosa a otra. Comunmente se dice de las enfermedádes contagiósas...").

Motolinía, like Judge Vázquez de Ayllón and many other eye-witness-chroniclers, used "pegar" to describe the spread of smallpox. To explain transmission from the natives of Fernandina to those of Cempoala, "han pegado" was chosen. Two decades later, Motolinía's Memoriales employed the same imagery: smallpox spread to the Indians ("pegar a los indios"). Meanwhile, Sahagún and his assistants, translating from the Nahuatl, describe death from smallpox as "the sticky [spreading?] disease" ("la muerte pegajosa") "of which many died, but others died only of hunger because no one cared for anyone else." When the first measles epidemic struck in 1531, Motolinía describes it as "jumping" (saltar) from a Spaniard: "and from him it jumped to the Indians, and if there had not been much advance warning so that they could be told, prepared and even preached that they not bathe or take other remedies contrary to the illness; and with this pleased the Lord so that not as many died as from smallpox; and they called this the year of the small leprosy (lepra) and for the first, the year of the great leprosy." The notion of the communicability of disease might not enter formal European discourse until the middle of the sixteenth-century, but, as early as 1431, the imagery was circulating in a Spanish medical manual written in the vernacular to facilitate its dissemination. Later, "pegar" appears frequently in the writings of the first conquistadores of New Spain.

Also mistaken is the argument that Motolinía simply wrote to emphasize parallels between the suffering of the chosen people in Egypt and natives in New Spain. Indeed, Motolinía recounts the Ten Plagues, but then, in a passage expunged from the Historia, challenges popular Spanish beliefs by contrasting the plagues of Biblical Egypt with those of contemporary New Spain:

Well considered, there are differences, great differences, between these plagues and those of Egypt. First, in only one of those [of Egypt], and that in the last, were there deaths of people; but here, in each of these there have been many deaths. Second, in each one of the houses there remained someone to mourn the dead, and here, of the plagues already described, many houses were left abandoned, because all their occupants died. Third, in Egypt, all the plagues lasted only a few days, and here, some a very long time. Those, by the commandment of God: most of these by the cruelty and depravity of men, although God permitted it...

The Franciscan was not guilty of mythopoesis, as Brooks would have it. Motolinía engaged his Catholic readers' religious beliefs--that the natives' afflictions were due to God's wrath--then, he disputed the commonplace thesis of conquest as fulfillment of Biblical prophesy by emphasizing the vast differences between the plagues of Egypt and those of New Spain. Historians who favor English translations miss the subtlety of Motolinía's argument because they, like Brooks, favor the Historia (first published in 1858; first English edition 1949) over the Memoriales (first published in 1903; no English translation). Confusion reigns because the original manuscripts of both are missing, and the extant copies are incomplete.

Since 1982 scholars have known, thanks to the detective work of the Mexican authority on Motolinía, Edmundo O'Gorman, that the Historia is an abridged version, indeed, "an atrocious mutilation" of the Memoriales. The Historia was extracted from the Memoriales, hastily edited and transcribed, perhaps dictated, certainly altered, probably in Spain by someone poorly-informed of conditions in New Spain, wholly ignorant of Nahuatl, unclear about the making of tortillas, and even wrong about the year the Franciscans first arrived in New Spain! Brooks compounds the folly by imagining the Memoriales to be a derivative of the Historia. Motolinía, an informed, sympathetic observer who entered New Spain in 1524, quickly became a skilled Nahuatl linguist and continued his ecclessiastical work in Mexico for almost forty-five years. He would not have committed the factual and linguistic errors unique to the Historia. O'Gorman argues that the Historia was constructed in Spain from Motolinía's Memoriales to provide testimony for revoking the New Laws. The mutilation of the text is so extensive that O'Gorman maintains that the Historia should no longer be attributed to Motolinía.

Sixteenth-century chroniclers--López de Gómara, Zorita, Cervantes de Salazar, Mendieta and Torquemada among others--favored the Memoriales, often quoting long passages from it. Brooks argues that Mendieta "simply copied" Motolinía, which he did (a fact widely recognized by modern historians who rarely cite Mendieta's account of the conquest), but it is the Memoriales that he relied upon, not the Historia. Twentieth-century historians and translators, unfortunately, favor the Historia. For our purposes this is a double misfortune, because the smallpox story in the Historia is an exaggeration of the Memoriales. The Historia subverts Motolinía's intentions by excising the contrasts present in the Memoriales. Indeed, the Historia compounds the offense by heightening the argument of divine punishment through the insertion of the phrase "y castigo esta tierra y a los que en ella se hallaron." The greatest distortion for our purposes is inflating the proportion dying from "half" to "more than half" and the number of provinces where this was the rule from "some" to "most". O'Gorman details many of the mutilations present in Motolinía's Historia, although he overlooks the embellishment of the fraction dying from smallpox. In any case, Crosby's first work on the subject, published in 1967, concluded that Motolinía's "proportion may be exaggerated, but perhaps not as much as we might think."

Taken as a whole, the more restrained account in the Memoriales bolsters the credibility of Motolinía's work. Motolinía did not distort his text to pander to the religious sensibilities of his readers or his own. He had no means of ascertaining the precise fraction of natives who died, but the order of magnitude which he chose ("one-half") did not come from Revelations, where "one-third" is the constant refrain. By using the fraction "one-half" his Spanish readers would infer that the force of the epidemic was enormous, of much greater magnitude than in Spain.

Spain and New Spain.

Since Brooks would reduce the epidemic of 1520 to a "mild attack of smallpox, such as occurred in contemporary Europe," a comparison with Europe, indeed with Spain, provides much needed perspective. For the period prior to 1492, Francisco Guerra identifies the most reliable sources of medical history as book-length manuscripts by three Jewish doctors--Samuel ben Waqar, Juan de Aviñón, and Alonso de Chirino. All rank smallpox among the most common, but not the most deadly, diseases of their time. Plague, on the other hand, was a different matter. For dealing with the plague, Chirino's practical guide for the lay-person, which he completed before 1431, offers two-bits of advice--first, pray, then flee as quickly as possible. For smallpox however, he recommends practical remedies. Noting that this is a disease which strikes mainly children, he prescribes a regimen of boiled barley water, chicken broth, and fresh fruit. Cold water should be administered frequently to the mouth, to prevent the disease from settling there or in the throat. To avoid blindness, the eyes should be washed five or more times a day with rose water. As the pox begins to wane the pustules should be permitted to dry-up completely and fall off freely without picking or scratching. Chirino's manual classifies smallpox with diseases that stick ("enfermedades que se pegan") and warns that the healthy should not go near, sleep with, nor be in close quarters with anyone ill with these diseases. He does not advise prayer or flight. Young children were innocent, and flight, uncalled for.

Aviñón's manual offers many intriguing observations about a variety of diseases, but for our purpose, his chronicle of epidemics and natural disasters for Seville from 1391 to 1420 is most instructive. He describes three smallpox epidemics striking Seville at intervals of some thirteen years, in 1393, 1407 and 1420. His entry for 1420 reads: "smallpox raged among the children, and many of them died; and it was a good year for bread and for wine."

For sixteenth-century Spain, Villalba's classic Epidemiología lists forty-nine epidemics, half attributed to plague ("peste") and six to smallpox. From the brevity of the passages on smallpox, Villalba does not seem to be greatly concerned with the disease. Likewise, Pérez Moreda's recent, comprehensive history of mortality crises in early modern Spain disposes of smallpox in a few pages. The period of greatest concern was the eighteenth-century, when efforts were being made to limit virulence. Two centuries earlier, smallpox was ubiquitous, but mortality crises due to the disease uncommon. According to Pérez Moreda, "the statements of the era unanimously assure that those who did not become ill with smallpox were very rare." Ashburn reports that "so common was smallpox in Spanish children that Ruy Díaz de Isla cited as remarkable the fact that he knew a man who had not had it until after his twentieth year."

Girolamo Fracastoro, the author of Contagion (1546), classifies smallpox with mild diseases of childhood, with chicken-pox and measles, that "attack children especially, adults rarely, the elderly hardly ever. But they seem to attack everyone once in life...." Fracastoro's translator notes that "since small-pox, under variolae, is so lightly treated by Fracastorius, as a malady to which practically everyone was then subject, it must have been a mild and rarely fatal strain." Indeed, according to the most authoritative modern study the strain or strains of smallpox common to that era were exceedingly benign throughout sixteenth-century Europe. Only in the following century and later does it become a virulent killer. Carmichael and Silverstein conclude:

Except for a few outbreaks in the fifteenth and sixteenth centuries, widely scattered in both space and time and quite atypical of the Variola major that would spread throughout Europe during the seventeenth-century, most medical, epidemiologic, and literary evidence points to the presence earlier of only a relatively mild endemic form of the disease.

In contrast, the smallpox which struck Amerindians, adults as well as children, was severe and often fatal. The impact of smallpox in Spain was wholly unlike that in New Spain. In Spain, it was a disease of childhood, whereas in New Spain the attack of 1520 struck all age groups, including many native leaders as shown above. Spanish eye-witnesses compared the outbreak with what had happened in the islands, not with anything in Spain or Europe. In New Spain, unlike Spain, smallpox was a lethal pestilence. If we assume that children made up one-third of the native population, then the crude rate of smallpox mortality among the natives would start at three-times the rate for European populations subjected to regular outbreaks of the disease. The absence of care and caretakers propelled smallpox mortality to catastrophic levels, but genetic factors probably played a role as well.

Smallpox morbidity and genetic diversity.

Genetic immunity is a common explanation for the enormous difference in death rates between Europeans and Amerindians, but there is no proof for this hypothesis. Few genetic differences distinguish New World populations from the Old, and none has a demonstrated advantage against the smallpox virus. Genetic diversity, rather than immunity, may be the key, as the viral epidemiologist Francis Black argues in a recent paper. Human geneticists report that Amerindians (along with Polynesians and New Guineans) are unusually homogeneous genetically. The smallpox virus adapts quickly to a host's immunological response--not mutating into a new strain, but rather preparing for battle with other hosts of nearly identical genetic make-up. Field research on measles is the most convincing. Measles acquired from a member of one's family tends to be more virulent than that acquired from a stranger. According to Black, "virus grown in one host is preadapted to a genetically like host and thereby gains virulence." The genetic key to successfully defending against an attack of virulent smallpox is the production of histocompatibility antigens. Unfortunately, in this regard, Amerindians show only 1/64th the genetic diversity of Africans or Europeans. The odds worsen when exposure is simultaneous and from multiple sources, particularly from members of one's own family. The close living quarters described by López de Gómara and Sahagún would heighten virulence as the smallpox spread through families and compactly-settled communities.


Whatever geneticists ultimately teach historians about immunity or diversity in explaining the virulence of the disease, the role of social agency is also important. We know, and the Spaniards knew, as Chirino's fifteenth-century practical medical manual makes clear, that nursing reduces smallpox mortality. While Europeans possessed no herbs, antibiotics, or prophylaxes, they, unlike the natives, understood that chances of recovery improved with care--water, food, and clean, warm clothing. What astonished Spanish eyewitnesses of this first epidemic was that it struck adults as well as children. In striking everyone at almost one blow, the attack left the population without care-givers or nurturers, a fact frequently noted in both Spanish and Nahuatl chronicles. Motolinía's Memoriales recounts the lethal effects of this horror: "because they all fell ill at a stroke, [the Indians] could not nurse one another, nor was there anyone to make bread, and in many parts it happened that all the residents of a house died and in others almost no one was left..."

Subsequent smallpox epidemics were less deadly because, on the one hand, lifetime immunity meant that survivors of an earlier epidemic were available to provide nursing and, on the other, Indians quickly adopted more appropriate methods of care. This change so impressed the mestizo chronicler Juan Bautista Pomar that his Relación del Texcoco (written in the 1580s) attributes better survival to improved care: "until they understood and became accustomed to wrap themselves and to sweat and to do other remedies that necessity and experience taught them with which afterwards here in other times when it [smallpox] has hit them, they have cured themselves...." The mestizo historian Diego Muñoz Camargo, in trying to account for the enormous mortality among the Tlaxcalans as a result of the new diseases, offered fatalism as an explanation: "they do not protect themselves from contagious illnesses; upon falling ill they are fatalistic and they permit themselves to die like beasts..." Muñoz Camargo's account for Tlaxcala is distinct from others in that it looks at the conquest from beyond the Central Basin, at a people who collaborated with the Spanish against the ancestral enemy, the Mexica, but who suffered a catastrophic decline anyway.

Brooks chides Spanish writers for their patronizing cultural chauvinism--that Indians had no cure for smallpox--but he wrongly imposes on their texts an anachronistic, late twentieth-century meaning for "cure," as in the elusive "cure for cancer." Among Spaniards in the sixteenth-century the most common meaning of "curar" was simply to care for or nurse the sick (which was precisely the point of Chirino's manual--to debunk the life-threatening cures of surgeons, physics and phlebotomists and provide the least damaging care), including the payment for care ("gasto de la cura") and assistance ("la assistencia del enfermo"). Likewise, for the Spanish "remedio," the modern English cognate may be deceptive. "Remedio" was defined broadly in the early modern era to include "medicine, or anything else, which serves to recover or maintain health."

The potency of nursing in reducing smallpox mortality is revealed in a recent study by Richard H. Frost, who reexamines an epidemic among the Hopi and Pueblo at the end of the nineteenth century. The shockingly high death rates among the Pueblo are well known, but the remedial effects of nursing is not given its due in scholarly histories, even though Crosby stressed its importance in his widely cited essay. Frost makes the case for nursing as follows:

Nursing never cured a case of smallpox: there never was such a cure at any time, in any country. But nursing often enabled the patients' own biological defenses to overcome the virus. This required assistance. People seriously afflicted with smallpox were incapable of nursing themselves, and were apt to die of exposure, desiccation, starvation, secondary infection, or despair and subsequent suicide, if others did not care for them.

Frost's re-analysis of the notorious epidemic of 1898/99 confirms an account by a Hopi administrator made almost a century ago. The report shows that among 421 Hopis infected by smallpox and who elected to receive care, only 24 died compared with 163 deaths in a settlement only half as large, but which declined care. These figures yield crude death rates of 6% and 74%, a twelve-fold increase for those without care. Nursing reduced smallpox mortality from catastrophic to tolerable levels. Those experienced with smallpox recognized the importance of nursing and often tried to alleviate suffering and thereby reduce the death toll. We do not know whether Cortés or his soldiers provided care for their Tlaxcalan allies, but we can be certain that their Mexica enemies received none because, while the epidemic enveloped Tenochtitlán, the only Spaniards remaining in the city were dead ones.


A quantitative assessment of the severity of the 1520 epidemic is impossible. At best a consensus on the order of magnitude may emerge from close analysis of a wide range of contemporary sources: early Spanish accounts, native annals, texts, and sixteenth-century histories which compare the relative devastation of war and the early epidemics.

Contemporary Spanish texts reveal that their authors were familiar with smallpox and smallpox mortality. The fact that chroniclers described the epidemic of 1520 in considerable detail suggests unusual severity. Vázquez de Ayllón, Cortés and others compare the attack with epidemics in the islands, and never with Spain. Motolinía, in the Memoriales but not in the Historia, contrasts smallpox mortality with deaths from the siege of Tenochtitlán stating that for the former the principal victims were the poor and the children ("pobres y pequeños"), while in the latter it was the lords and the leaders ("señores y principales"). Most of the castellanos who accompanied Cortés did not say or write much about the conquest, but those who did so extensively commented on the devastation of the pestilence. , In a claim to the crown for compensation as a participant in the siege of Tenochtitlán, Bernardino Vázquez de Tapia testified in the early 1540s that:

The pestilence of measles and smallpox was so severe and cruel that more than one-fourth of the Indian people in all the land died--and this loss had the effect of hastening the end of the fighting because there died a great quantity of men and warriors and many lords and captains and valiant men against whom we would have had to fight and deal with as enemies, and miraculously Our Lord killed them and removed them from before us.

Native annals, unlike Spanish chronicles, record the most important events for each year. Before 1519 native annals report pestilence or famine only when devastation was prolonged, often for a year or more. In the century before European instrusion (1420-1519), the Annals of Cuauhtitlan report seven famines and two epidemics--all multi-year phenomena. Then, for 1520, the most notable event was smallpox, when the death of two leaders from the disease is logged. Since smallpox outbreaks remain in any one place only for a couple of months, it should be surprising to find smallpox recorded. Yet, 1520 is often named the year-of-the-pox in native annals, such as the Annals of Tlatelolco and the Annals of Tenochtitlán (Codex Aubin). One of the most interesting annals, the Códice Telleriano Remensis, is rendered useless by the loss of pictographs for 1516 through 1527. Of the surviving pictographs for the post-conquest period, 1528 through 1560, this Códice records four epidemics: measles (1531), smallpox (1538), a great mortality ("una gran mortandad," 1544-45), and mumps (1550).

If we examine Nahuatl texts written in the Roman alphabet the horror of smallpox is told again and again. The longest native text is in Sahagún's monumental ethnohistorical treatise, the General History of the Things of New Spain. A distillation of testimony of Nahua leaders and informants in three towns, the clinical, yet melancholic descriptions have made this one of the most widely cited Nahautl texts on the conquest. English translations are available in three editions. The first, published in 1955 by Dibble and Anderson, is often cited in extenso. Brooks uses the second translation, published in 1975. I favor a third by Lockhart (1993), the first to offer English translations of both the original Nahuatl (probably completed in 1555) and the accompanying Spanish gloss (written before 1586). Lockhart's translation reads:

Twenty-ninth chapter, where it is said how, at the time the Spaniards left Mexico, there came an illness of pustules of which many local people died; it was called 'the great rash' (smallpox).

Before the Spaniards appeared to us [again], first an epidemic broke out, a sickness of pustules. It began in Tepeilhuitl ['which is at the end of September,' according to the accompanying Spanish gloss]. Large bumps spread on people, some were entirely covered. They spread everywhere, on the face, the head, the chest, etc. (The disease) brought great desolation; a great many died of it. They could no longer walk about, but lay in their dwellings and sleeping places, no longer able to move or stir. They were unable to change position, to stretch out on their sides or face down, or raise their heads. And when they made a motion, they called out loudly. The pustules that covered people caused great desolation; very many people died of them, and many just starved to death; starvation reigned, and no one took care of others any longer.

On some people, the pustules appeared only far apart, and they did not suffer greatly, nor did many of them die of it. But many people's faces were spoiled by it, their faces and noses were made rough. Some lost an eye or were blinded.

The disease of the pustules lasted a full sixty days; after sixty days it abated and ended. When people were convalescing and reviving, the pustules disease began to move in the direction of Chalco. And many were disabled or paralyzed by it, but they were not disabled forever. It broke out in Teotl eco, and it abated in Panquetzaliztli. The Mexica warriors were greatly weakened by it.

Brooks interprets the 1975 translation of this passage as evidence that "it is reasonable to credit their collective memory with knowledge that not many died" even though the text itself states unequivocally that the pustules brought "great desolation," that "very many died" and "many just starved to death." His revisionist zeal divines the ever-present hand of Motolinía in this passage, but consider Sahagún's own explanation of how the manuscript was composed:

When this manuscript was written (which is now over thirty years ago [i.e., 1555]) everything was written in the Mexican language and was afterwards put into Spanish. Those who helped me write it were prominent elders, well versed in all matters, relating not only to idolatry but also to government and its offices, who were present in the war when this city was conquered.

Indeed, Chapter 29, unlike the Spanish chronicles, reads like a pictorial history of the Nahuas' suffering, rendered in their own words. Lockhart characterizes the entire book as "authentic oral tradition with an emphasis on visuality" and "an authentic expression of indigenous people." "Signs of active intervention by Sahagún are minimal." Motolinía's influence was nil. Sahagún thought the Nahua account to be so one-sided and anti-Spanish that, to redress the balance, he wrote his own history of the conquest, which he completed in 1585. The comparable passage of Sahagún's Conquest offers the Spanish view. Note the shift from visual description to interpretive synthesis:

During this epidemic, the Spaniards, rested and recovered, were already in Tlaxcala. Having taken courage and energy because of reinforcements who had come to them and because of the ravages of the [Mexican] people that the pestilence was causing, firmly believing that God was on their side, being again allied with the Tlaxcalans, and attending to all the necessary preparations to return against the Mexicans, they began to construct the brigantines...

Historians and chroniclers began to compare the severity of the various epidemics toward the middle of the sixteenth-century. Motolinía, writing in 1542, saw three great devastations, which he sought to fit to years ending in "one," the most important being the war, pestilence and famine of "1521". Several years after his manuscript was shipped to Spain (and while its author was in Guatemala), the great devastation of 1545 broke out so we cannot know how his numerology would have taken this into account.

On November 8, 1576, as the third great epidemic of the century unfolded, Sahagún, in a rare direct intervention in the General History and for which there is no corresponding Nahuatl text, mused whether the present plague would exterminate the native people. He addressed the question directly and forcefully, leaving no doubt that the smallpox attack of 1520 was exceedingly lethal ("murio casi infinita gente")--more deadly even than the war--but the deadliest was the matlazahuatl epidemic of 1545, "a very great and universal pestilence where, in all of New Spain, the greater part of the people who lived therein died." In Tlatelolco alone Sahagún claimed to have buried 10,000 and fell ill to the disease himself. While he wrote in November 1576, the number of deaths mounted daily. According to Sahagún, many were dying of hunger, without care, and with no one even to provide a jar of water--charitable relief having been exhausted. He feared that if the contagion continued for another three or four months there would be no natives left, that the land would revert to wild beasts and wilderness. He reasoned that Spaniards were too few to settle the land, and the Indians were becoming extinct.

Pomar, the historian of the city of Texcoco, also singled out three great epidemics of the century, 1520, 1545, and 1576, but characterized that of 1520 as the worst. He reported that Texcoco, which surrendered to Cortés without a struggle, used to number some 15,000 citizens ("vecinos") but did not have 600 as he wrote in the 1580s. Many smaller subject villages had disappeared entirely.

I prefer the most explicitly quantitatively-reasoned assessment, that by Muñoz Camargo for the province of Tlaxcala also drafted in the 1580s but only published in 1981:

I say that the first [1520] ought to be the greatest because there were more people, and the second [1545] was also very great because the land was very full [of people], and this last one [1576] was not as great as the first two because although many people died many escaped with the remedies that the Spaniards and the religious people provided...

Evidence from a wide variety of sixteenth-century Spanish and Nahuatl sources point to a single conclusion: the smallpox epidemic of 1520 ranked among the three worst mortality crises of the century. The death rate from smallpox and starvation in 1520/21 was probably less than for the matlazahuatl epidemics of 1545/46 and 1576/77. Nonetheless, if we accept the intelligence offered by one of the most celebrated native chroniclers of the colonial era, the smallpox epidemic of 1520 was the greatest demographic catastrophe of the century for the Nahuatl-speaking people of Central Mexico.

The Consensus on population decline.

Raging disagreement over the size of the pre-contact native population obscures the widespread consensus that the sixteenth-century was a demographic catastrophe for the native peoples of Central Mexico and that disease, exploitation and ecological disruption were the principal agents. All population figures for the early modern era are riddled with errors of every conceivable kind. Yet, for some historians, narrative is easily misread, generalization difficult to elicit, or, perhaps number simply has its own fascination. Table 3 offers a summary of population figures at two points in the sixteenth-century, 1519 and 1595, for all the most widely-cited, authoritative efforts. The last column of the table reports the percentage of population decline over the century implied by each set of figures. Where authors report ranges rather than a single number, these are included in the table. Figure 1 depicts the percentage of population decline over the century implied by the figures of these authorities. Included are data for "Mexico"--Cook and Borah's area of a half-million square kilometers (but excluding Yucatán, Chiapas, and the North)--the Central Valley and Kubler's 128 towns in Central Mexico, Michoacán and Oaxaca. Figures for the total population of "Mexico" at contact range from 4.5 million (Rosenblat, Aguirre-Beltrán) to 30 million (Cook and Borah). This enormous span reflects the paucity of data as well as fundamental disagreement over how the few data that are available should be interpreted. If a number for the native population in 1519 is desired, a lengthy chain of supposition and extrapolation is required. Even so, some figures are more nearly guesses than others.

Rosenblat, the Argentine linguist (he always disclaimed the sobriquet "historical demographer," which others seek to bestow), characterizes his work as nothing more than a "vague approximation" "without fanaticism" based on "likelihood" or a "reasonable probability," but "the only feasible" nonetheless. Over three decades of publishing on this subject (1935-1967), Rosenblat scarcely revised a figure--nor was his widely cited work subjected to the slightest scholarly scrutiny. For Mexico, he chose numbers compiled by the royal chronicler López de Velasco before 1570, particularly those for individual towns and villages. For 1492, Rosenblat refers the reader to an appendix of sources, but none are listed for Mexico before 1570. In its place, he criticizes the figures of Mexicanists such as Mendizabal and Kubler.

Rosenblat reasons that his pattern of change is basically in agreement with that of Kubler (who writes of "appalling mortality in the sixteenth-century"), but this is not the case. Figure 1 makes clear that Rosenblat stands alone in defense of a decline in the native population of less than 25%. His position would be unproblematic if he stood on solid ground. His sympathy for Kubler's figures, which point to a fifty percent drop over the century, does not extend to an acceptance of the pattern of decline sketched by Kubler's work. Likewise, Rosenblat accepts López de Velasco's figures, but ignores the chronicler's narrative accompanying his numbers. López de Velasco, after studying a vast array of information compiled by the imperial bureaucracy, concludes that for the realm as a whole "in the beginning the natives were many more in number than there were afterward, because in many provinces, where there used to be a great multitude of them, they have reached almost the point of extinction." In other places, he sees the population as recovering, but from the relative extent of his text, López de Velasco was clearly more attentive to decline than recovery.

Rosenblat criticizes the catastrophe school of contact demography for failing to take into account the recovery potential of the native population. His objection went unmet until recently, when Thomas Whitmore published a series of wide-ranging, sophisticated epidemiological simulations. Some will dismiss this work as historical fiction of a quantitative sort, but Whitmore's simulations offer a partial answer to Rosenblat's question about the role of demographic recovery between epidemics. From Whitmore's simulations, based on morbidity and mortality rates obtained from scrutinizing the world-wide historical record, we learn that the likely levels of epidemic mortality probably overwhelmed the homeostatic potential of the indigenous population--even without taking into account deaths due to war or social and environmental disruption. The simulations also reveal what Rosenblat fails to appreciate--the devastation of epidemic disease. Rosenblat reasoned:

If in fact I did derive moderate and even low figures for the 1492 population, it was not because I had intended to do so. The data I had about the Conquest allowed no other choice, unless one were to assume vast and horrible killing, which requires a macabre imagination and which I found unacceptable given the known extermination techniques of the sixteenth-century.

Had Rosenblat paid greater attention to the texts of López de Velasco and other early chroniclers, he might have considered a second option--disease. My study of Rosenblat's sources for Mexico and the considerable body of other texts reviewed in this paper leads me to reject his vague approximations on precontact populations, and, more importantly, reject the pattern of demographic decline which his figures imply. Attentive readers of the Spanish and Nahuatl narratives witness a demographic catastrophe, indeed a succession of catastrophes, of unsustainable magnitudes. If numbers are required to comprehend this, they must agree with the narratives.

At the opposite pole stand Cook and Borah's figures, but they are not entirely alone. Clavijero, writing at the end of the eighteenth-century, also suggested 30 million as a possible figure, but noted at the same time that any number is subject to a wide margin of error. Cook and Borah's numbers are an order of magnitude greater than most that preceded them and have provoked the greatest controversy and disbelief. The Berkeley empiricists sought to move the debate from the arena of belief to evidence, by using the documentation on tribute paid by subject towns. The long chain of assumptions and conversion factors necessary to transform tax payments into tax payers convince many students of the subject that the exercise is untrustworthy. Yet, their writings are less dogmatic than critics would have us think. Borah noted many years ago: "The more the number of agents and agencies entering into the gathering and processing of materials, the wider are the margins of error. ... For those [estimates of population] of the first century, it seems likely that the most we can hope for is estimates of the order of magnitude." Cook and Borah's figure of 25.2 million for the contact population of Mexico is widely cited, but as far as I can recall, no one cites their range of figures--18-30 million. Their critics--Rosenblat, Sanders, Zambardino and others--might reply that even this range is a wild exaggeration. What I find remarkable in Figure 1 is the correspondence among scenarios of demographic disaster, theirs and their critics--with the exception of Rosenblat.

For smaller areas, population estimates require less extrapolation, and the range of uncertainty contracts accordingly. All the researchers on this subject who rely on primary sources--Mendizabal, Kubler, Rosenblat, Gerhard, Gibson, Cook and Borah and Sanders--encourage research at the local level. Thus, Sanders' estimate for the "Central Mexican symbiotic region" is based on a sampling of archaeological excavations and tribute lists sprinkled over an area of "only" a thousand square miles. Similarly, Gibson and Kubler compile figures for a select group of settlements with data at two or three points over the sixteenth-century. Mendizabal developed a detailed portrait for towns in Michoacán, and his figure for "Mexico" is based on bold extrapolations from those data, which he then used to adjust the calculations of the Italian scholar, Dino Camavitto. At finer levels of analysis, the same ghastly picture emerges, a demographic collapse of 50-80%, even when settlements which disappeared entirely are excluded from analysis (the method deliberately chosen by Kubler).


Consensus is emerging on the scale, causes, and consequences of the demographic disaster which struck sixteenth-century Mexico. There is agreement that a demographic catastrophe occurred and that epidemic disease was a dominant factor in initiating a die-off, beginning, in Mexico, with smallpox in 1520. But the role of disease cannot be understood without taking into account massive harsh treatment (forced migration, enslavement, abusive labor demands and exhorbitant tribute payments) and ecological devastation accompanying Spanish colonization. Killing associated with war and conquest was clearly a secondary factor, except in isolated cases, such as the devastation of Cholula or the leveling of Tenochtitlán.

A fair-minded cross-examination of the broad range of primary sources for the epidemic of 1520 leaves little doubt that smallpox swept throughout the Central Mexican Basin, causing enormous mortality. The epidemic ranked with the deadliest disasters that native annals customarily recorded. Whether the fraction of smallpox deaths was one-tenth or one-half, we have no way of knowing, but from my reading of the texts discussed here, the true fraction must fall within these extremes, perhaps near the mid-point.

David Henige recently staked out the iconoclast's position on pre-contact population size: "despite three centuries of sporadic guessing, culminating in fifty years of intensive investigation, it is still not possible to claim that any number, or any range of numbers beyond a certain irreducible minimum, is significantly more likely than any other number or range of numbers." If we leave aside the controversy over numbers, there emerges a broad agreement in the Spanish and Nahuatl narratives and in the patterns of decline sketched by historians. After almost five centuries of writing on the subject, there is a consensus that a demographic catastrophe occurred in sixteenth-century Mexico. For narrative-bound historians, there exists a great library of published Spanish and Nahuatl texts on the demographic misfortunes of conquest and early colonization.

For historians who abide quantification, expert guesstimates point to overall levels of demographic destruction over the sixteenth-century for Central Mexico exceeding 50%, probably ranging beyond 75%, and even topping 90% in some large regions such as the tropical lowlands. Vociferous critics of the Cook and Borah figures often overlook similarities with their own scenarios of demographic collapse. To reduce historiographical uncertainty further will require much additional, careful sifting of archival and archaeological evidence--tasks which, in recent decades, few seem inclined to undertake.

In the meantime, I find convincing the testimony of the Oidor Licenciado Francisco Ceynos, who sums up the opinion of many enlightened sixteenth-century Spanish observers. Ceynos, after five years as fiscal on the Royal Council of the Indies, arrived in Mexico in 1530 to sit on the Real Audiencia of Mexico City. A royal judge (oidor) for more than thirty years, he fought against the widespread practice of enslaving Indians and against the extreme labor and tribute burdens common in that era. On March 1, 1565, he completed a lengthy recommendation on colonization policies suitable for newly conquered regions. As preamble he reviewed briefly the demographic history of Spanish colonization in Mexico:

...and it is certain that from the day that D. Hernando Cortés, the Marquis del Valle, entered this land, in the seven years, more or less, that he conquered and governed it, the natives suffered many deaths, and many terrible dealings, robberies and oppressions were inflicted on them, taking advantage of their persons and their lands, without order, weight nor measure; ...the people diminished in great number, as much due to excessive taxes and mistreatment, as to illness and smallpox, such that now a very great and notable fraction of the people are gone, and especially in the hot country.

We do not know what number, percentage or ratio Judge Ceynos had in mind for "grandes muertes," "gran cantidad" or "faltó muy grande y notable parte de la gente," but what he wrote has the ring of truth. He reported a disaster on a scale unimaginable to contemporary Europeans. If five centuries later this thesis remains beyond the domain of "reasonable probability" for some historians, their number, too, is diminishing as the evidence of demographic catastrophe accumulates.


Notes are omitted from this web version.