As well-trained, methodical butchers of the battlefield and as citizens of the land of the Inquisition, Cortés and his men, who arrived in Mexico in 1519, were inured to displays of cruelty and bloodshed. It must have come as no great surprise to them that the Aztecs methodically sacrificed human beings, inasmuch as the Spaniards and other Europeans methodically broke people's bones on the rack, pulled people's arms and legs off in tugs-of-war between horses, and disposed of women accused of witchcraft by burning them at the stake. Still, they were not quite prepared for what they found in Mexico.

Nowhere else in the world had there developed a state-sponsored religion whose art, architecture and ritual were so thoroughly dominated by violence, decay, death and disease. Nowhere else were walls and plazas of great temples and palaces reserved for such a concentrated display of jaws, fangs, claws, talons, bones and gaping death heads. The eyewitness accounts of Cortés and his fellow conquistador, Bernal Díaz, leave no doubt concerning the ecclesiastical meaning of the dreadful visages portrayed in stone. The Aztec gods ate people. They ate human hearts and they drank human blood. And the declared function of the Aztec priesthood was to provide fresh human hearts and human blood in order to prevent the remorseless deities from becoming angry and crippling, sickening, withering, and burning the whole world.

The Spaniards first glimpsed the inside of a major Aztec temple as the invited guests of Moctezuma, the last of the Aztec kings. Moctezuma had not yet made up his mind concerning Cortés's intentions – an error which was shortly to prove fatal for him – when he invited the Spaniards up 114 steps to the twin temples of Uitzilopochtli and Tlaloc, which stood at the top of Tenochtitlán's tallest pyramid in the centre of what is today Mexico City. As they mounted the steps, wrote Bernal Díaz, other temples and shrines ‘all gleaming white’ came into view. In the open space at the top of the pyramid ‘the great stones stood on which they placed the poor Indians for sacrifice.’ Here also was ‘a bulky image like a dragon, and other evil figures and much blood shed that very day.’ Then Moctezuma let them see the image of Uitzilopochtli, with its ‘very broad face and monstrous and terrible eyes,’ before which ‘they were burning the hearts of three Indians whom they had sacrificed that day.’ The walls and floor of the temple ‘were so splashed and encrusted with blood that they were black’ and the ‘whole place stank vilely.’ In Tlaloc's temple, too, everything was covered with blood, ‘both walls and altar, and the stench was such that we could hardly wait for the moment to get out of it.’

The main source of food for the Aztec gods was prisoners of war, who were marched up the steps of the pyramids to the temples, seized by four priests, spread-eagled backward over the stone altar, and slit open from one side of the chest to the other with an obsidian knife wielded by a fifth priest. The victim's heart – usually described as still beating – was then wrenched out and burned as an offering. The body was rolled down the pyramid steps, which were built deliberately steep to accommodate this function.

Occasionally some sacrificial victims – distinguished warriors, perhaps – were given the privilege of defending themselves for a while before they were killed. Bernardino De Sahagún, the greatest historian and ethnographer of the Aztecs, described these mock battles as follows:

... they slew other captives, battling with them – these being tied, by the waist, with a rope which passed through the socket of a round stone, as of a mill; and the rope was long enough so that the captive might walk about the complete circumference of the stone. And they gave him arms with which he might do battle; and four warriors came against him with swords and shields, and one by one they exchanged sword blows with him until they vanquished him.

Apparently in the Aztec state of two or three centuries earlier the king himself was not beyond the task of dispatching a few victims with his own hands. Here is an account by Diego Durán of the legendary slaughter of prisoners captured among the Mixtecs:

The five priests entered and claimed the prisoner who stood first in the line... Each prisoner they took to the place where the king stood and, when they had forced him to stand upon the stone which was the figure and likeness of the sun, they threw him upon his back. One took him by the right arm, another by the left, one by his left foot, another by his right, while the fifth priest tied his neck with a cord and held him down so that he could not move.

The king lifted the knife on high and made a gash in the breast. Having opened it he extracted the heart and raised it high with his hand as an offering to the sun. When the heart had cooled he tossed it into the circular depression, taking some of the blood in his hand and sprinkling it in the direction of the sun.

Not all the victims were prisoners of war. Substantial numbers of slaves were also sacrificed. In addition, certain youths and maidens were chosen to impersonate specific gods and goddesses. These were treated with great care and tenderness throughout the year preceding their execution. In the Dresden Codex, a sixteenth-century book written in Nahuatl, the language of the Aztecs, there is this account of the death of a woman who played the role of the goddess Uixtociuatl:

And after they had slain the captives, only then Uixtociuatl's impersonator followed; she came only at the last. They came to the end and finished only with her.

And when this was done, thereupon they laid her down upon the offering stone. They stretched her out upon her back. They laid hold of her; they pulled and stretched out her arms and legs, bending up her breast greatly, bending down her back, and stretching down her head taut, toward the earth. And they bore down upon her neck, with the tightly pressed snout of a sword fish, barbed, spiny; spined on either side.

And the slayer stood there; he stood up. Thereupon he cut open her breast.

And when he opened her breast, the blood gushed up high; it welled up far as it poured forth, as it boiled up.

And when this was done, then he raised her heart as an offering to the god and placed it in the green jar, which was called the green stone jar.

And as this was done, loudly were the trumpets blown. And when it was over, then they lowered the body and the heart of the likeness of Uixtociuatl, covered by a precious mantle.

But such displays of reverence were few and far between. The great majority of victims did not walk joyfully up the steps of the pyramid, soothed by the prospect that they were about to make some god happy. Many of them had to be dragged by the hair:

When the masters of the captives took their slaves to the temple where they were to slay them, they took them by the hair. And when they took them up the steps of the pyramid, some of the captives swooned, and their masters pulled them up and dragged them by the hair to the sacrificial stone where they were to die.

The Aztecs were not the first Mesoamericans to sacrifice human beings. We know that the Toltec and the Maya engaged in the practice, and it is a reasonable inference that all steep-sided, flat-topped Mesoamerican pyramids were intended to serve as a stage for the spectacle in which human victims were fed to the gods. Nor was human sacrifice an invention of state-level religions. To judge from the evidence of band and village societies throughout the Americas and in many other parts of the world, human sacrifice long antedated the rise of state religions.

From Brazil to the Great Plains, American Indian societies ritually dispatched human victims in order to achieve certain kinds of benefits. Virtually every element of Aztec ritual was foreshadowed in the beliefs and practices of band and village peoples. Even the preoccupation with the surgical removal of the heart had its precedents. The Iroquois, for example, vied with each other for the privilege of eating the heart of a brave prisoner so that they could acquire some of his courage. Everywhere, male prisoners were the chief victims. Before being killed, they were made to run a gauntlet, or were beaten, stoned, burned, mutilated, or subjected to other forms of torture and abuse. Sometimes they were tied to stakes and given a club with which to defend themselves against their tormentors. Occasionally one or two prisoners were kept for extended periods and provided with good food and concubines.

The ritual sacrifice of prisoners of war among band and village peoples was usually followed by the eating of all or part of the victim's body....

We can see that the unique contribution of the Aztec religion was not the introduction of human sacrifice but its elaboration along certain destructive pathways. Most notably, the Aztecs transformed human sacrifice from an occasional by-product of luck on the battlefield to a routine in which not a day went by when someone was not spread-eagled on the altars of the great temples such as Uitzilopochtli and Tlaloc. And sacrifices also took place at dozens of lesser temples ranging down to what might be called neighbourhood chapels. One such neighbourhood facility – a low, circular, flat-topped structure about twenty feet in diameter – was excavated during the construction of Mexico City's subway. It now stands, preserved behind glass, at one of the busiest stations. For the less-than-total enlightenment of the crowds of commuters who pass it every day, an accompanying plaque notes only that the ancient Mexicans were ‘very religious.’

Since the Aztec armies were thousands of times bigger than those of the Huron or the Tupinamba, they could capture thousands of prisoners in a single battle. In addition to daily sacrifices of small numbers of prisoners and slaves at major and minor shrines, then, mass sacrifices involving hundreds and thousands of victims could be carried out to commemorate special events. The Spanish chroniclers were told, for example, that at the dedication in 1487 of the great pyramid of Tenochtitlán four lines of prisoners stretching for two miles each were sacrificed by a team of executioners who worked night and day for four days. Allotting two minutes per sacrifice, the demographer and historian Sherburne Cook estimated that the number of victims associated with that single event was 14,100. The scale of these rituals could be dismissed as exaggerations were it not for the encounters of Bernal Díaz and Andrés de Tápia with methodically racked and hence easily counted rows of human skulls in the plazas of the Aztec cities. Díaz writes that in the plaza of Xocotlan

there were piles of human skulls so regularly arranged that one could count them, and I estimated them at more than a hundred thousand.

I repeat again there were more than one hundred thousand of them.

Of his encounter with the great skull rack in the centre of Tenochtitlán, Tápia wrote:

The poles were separated from each other by a little less than a vara approximately a yard's length, and were crowded with cross sticks from top to bottom, and on each cross stick were five skulls impaled through the temples: and the writer and a certain Gonzalo de Umbría, counted the cross sticks and multiplying by five heads per cross stick from pole to pole, as I said, we found that there were 136 thousand heads.

But that was not all. Tápia also describes two tall towers made entirely out of skulls held together by lime in which there was an uncountable number of crania and jaws....

So intent were the Aztecs on bringing back prisoners to be sacrificed that they would frequently refrain from pressing a military advantage for fear that they would kill too many enemy troops before terms of surrender could be arranged. This tactic cost them dearly in their engagements with Cortés's troops, who from the Aztec point of view seemed to be irrationally intent upon killing everyone in sight....

Conventional descriptions of the Aztec ritual of sacrifice end with the victim's body tumbling down the pyramid. Blinded by the image of a still-beating heart held aloft in the hands of the priest, one can easily forget to ask what happened to the body when it came to rest at the bottom of the steps. Michael Harner of the New School has pursued this question with greater intelligence and courage then anyone else. Throughout the rest of this chapter I shall draw heavily upon his work. He alone deserves the credit for solving the riddle of Aztec sacrifice.

As Harner points out, there really is no mystery concerning what happened to the bodies since all the eyewitness accounts are in fundamental agreement. Anyone with a knowledge of how the Tupinamba, the Huron and other village societies disposed of their sacrificial victims should be able to come to the same conclusion: the victims were eaten. Bernardino De Sahagún's description leaves little room for doubt:

After having torn their hearts from them and poured the blood into a gourd vessel, which the master of the slain man himself received, they started the body rolling down the pyramid steps. It came to rest upon a small square below. There some old men, whom they called Quaquacuiltin, laid hold of it and carried it to their tribal temple, where they dismembered it and divided it up in order to eat it.

De Sahagún makes the same points repeatedly:

After they had slain them and torn out their hearts, they took them away gently, rolling them down the steps. When they had reached the bottom, they cut off their heads and inserted a rod though them, and they carried the bodies to the houses which they called calpulli, where they divided them up in order to eat them.

... and they took out their hearts and struck off their heads. And later they divided up all the body among themselves and ate it...

Diego Durán gives us a similar description:

Once the heart had been wrenched out it was offered to the sun and blood sprinkled toward the solar deity. Imitating the descent of the sun in the west the corpse was toppled down the steps of the pyramid. After the sacrifice the warriors celebrated a great feast with much dancing, ceremonial and cannibalism.

These descriptions clarify a number of points about the Aztec warfare-sacrifice-cannibalism complex. Harner notes that each prisoner had an owner – probably the officer in charge of the soldiers who actually made the capture. When the prisoner was brought back to Tenochtitián, he was housed in the owner's compound. We know little about how long he was kept there or how he was treated, but one can guess that he was fed enough tortillas to keep him from losing weight. It even seems likely that a powerful military commander would have kept several dozen prisoners on hand, fattening them up in preparation for special feast days or important family events such as births, deaths or marriages. When the time for sacrifice approached, the prisoners may have been tortured for the instruction and amusement of the owner's family and neighbours. On the day of the sacrifice, the owner and his soldiers no doubt escorted the prisoner to the foot of the pyramid to watch the proceedings in the company of other dignitaries whose prisoners were being sacrificed on the same day. After the heart was removed, the body was not tumbled down the steps so much as pushed down by attendants, since the steps were not steep enough to keep the body moving all the way from top to bottom without getting stuck. The old men, whom De Sahagún refers to as Quaquacuiltin, claimed the body and took it back to the owner's compound, where they cut it up and prepared the limbs for cooking – the favourite recipe being a stew flavoured with peppers and tomatoes. De Sahagún states that they put ‘squash blossoms’ in the flesh. The victim's blood, as De Sahagún notes, was collected in a gourd vessel by the priests and delivered to the owner. We know the heart was put into a brazier and burned along with copal incense, but whether or not it was burned to ashes remains unclear. There is also some question concerning the fate of the trunk with its organs and the head with its brains. Eventually, the skull ended up on display on one of the racks described by Andrés Tápia and Bernal Díaz. But since most cannibals relish brains, we can assume that these were removed – perhaps by the priests or spectators – before the skulls ended up on exhibit. Similarly, although according to Díaz the trunk was tossed to the carnivorous mammals, birds and snakes kept in the royal zoo, I suspect that the zoo keepers – Tápia says that there were large numbers of them – first removed most of the flesh.

I have been pursuing the fate of the victim's body in order to establish the point that Aztec cannibalism was not a perfunctory tasting of ceremonial titbits. All edible parts were used in a manner strictly comparable to the consumption of the flesh of domestic animals. The Aztec priests can legitimately be described as ritual slaughterers in a state-sponsored system geared to the production and redistribution of substantial amounts of animal protein in the form of human flesh. Of course, the priests had other duties, but none had greater practical significance than their butchery.