Population Crises and Population Cycles

9. Central Mexico and the Andes to the Conquests

In May 1522 Hernan Cortes wrote to the Holy Roman Emperor Charles V (Charles I of Spain), describing his conquest the previous August of the Aztec city of Tenochtitlan on Lake Texcoco in the Valley of Mexico. ‘No race’, he wrote, ‘however savage, has ever practised such fierce and unnatural cruelty as the natives of these parts’ (transl. Pagden, 1971). One can sympathise with Cortes: he had had a gruelling time restraining his Tlaxcalan allies from killing and eating all the Aztec women and children. But of course the Mexicans are not and were not inherently crueller than other peoples. They were simply experiencing the worst population crisis in recorded history, ending in a population crash unique in combined scale and proportions (Figure 1).

In Mexico as in the Old World, irrigation and terracing had brought about high population density, cities, division of labour, trade, and social stratification. The cultivation of chinampas, floating islands on lakes, made possible very high population densities even by Egyptian or Chinese standards - up to 360 people per square kilometre. A succession of brilliant centres of civilisation arose (Table 1), to succumb in turn to population crises, with famines, epidemics and often destruction of the cities (La Venta, Teotihuacan, Tollan). Barbarians invaded from the North, and set up progressively more stressful civilisations, the Toltecs, the Tepanecs and finally the Aztecs, who conquered almost the whole of Mexico in the fifteenth century AD.

The Aztecs were as brutally militaristic as the watershed empires of the Old World: they burned books, ruled by terror, and brought up their own children with cruel punishments. But for lack of major river systems, theirs was not a centralised but a tributary empire, extracting loot (including two tonnes of gold per year) from subject cities, and harrying the few independent ones, such as Tlaxcala, with raids. By tribute and capture they obtained victims for human sacrifice.

This very unpleasant form of stress culture developed early (in Teotihuacan) in this chronically overpopulated land. Among the Aztecs, the luckier victims had their hearts torn out; the less lucky were roasted alive. Before being sacrificed, children had their nails torn out to make them weep copiously, as a (sympathetic magic) hint to the rain-god. The best human meat was eaten by the upper classes, the rest was thrown to the animals in the Emperor’s zoo. The whole culture of the Aztec empire was built around human sacrifice. The practice was endemic in the tributary and independent cities, as well as among the Aztecs themselves.

In the later fifteenth century, human sacrifice reached an unparalleled scale, with tens of thousands of victims, as one symptom of the terrible final population crisis in Mexico, and especially among the Aztecs, beginning with a serious famine in the 1450s. The Aztec population density was so high that, in addition to their very productive chinampa agriculture, they had to import as tribute 2700 tonnes of maize per year. Class divisions became rigid and extreme, the swollen army was always suppressing revolts, and wars with the independent cities became fiercer and more frequent. And the crisis finally made the Aztecs vulnerable to the Spanish Conquest of 1519-1521.

The invading force had the (then) best soldiers of Europe, including Amazons such as Maria de Estrada, who handled sword and lance as well as any man, the incomparable leadership of Cortes, and the brilliant diplomacy of his loyal and very intelligent Mexican mistress Marina. They had horses, steel weapons, fire-arms, guns, and ships for use on Lake Texcoco built by the master shipwright Martin Lopez. But this force, never more and often less than a thousand strong, could not possibly have conquered an empire of millions without a catastrophic population crisis and the universal hatred felt for the Aztecs by all the other Mexicans. Without the coastal Totonacs, as one Spaniard admitted, they could not have beaten the Tlaxcalans and turned them into loyal allies. Without the Tlaxcalans, they could not have beaten the Aztecs. When the Spaniards had been driven out of Tenochtitlan, and their cause seemed hopeless, a Tlaxcalan chief persuaded his people not to change sides, ‘by vividly recalling the habitual treachery, the continual cruelty, and the customary arrogance’ of the Aztecs (Thomas, 1994).

Cortes shared his conquest with Mexican nobles, including Aztec princes. After he lost control, many Spanish and Mexican lords oppressed their Mexican peasants. But Cortes was himself responsible for the supreme demographic catastrophe, by beginning the import of worse enemies than smallpox - sheep and cattle. Between 1520 and 1620, the Spanish authorities made land grants in Mexico of 44,000 square kilometres for cattle ranches and 31,000 square kilometres for sheep farms, to be stocked at 28 cattle and 257 sheep per square kilometre. The animals roamed freely over native croplands. By 1620, overgrazing had turned large areas to wilderness and caused widespread erosion and valley floods. This drastic decline in land productivity was probably the most important factor of all in the population crash.

In the Andean region, hydraulic civilisation was made possible by irrigation based on a number of rivers running in parallel from the high plateau of the Andes through the arid coastal desert to the Pacific. Several brilliant civilisations arose here in both highlands and desert (Table 2), until progress was halted when the whole region was conquered in the later fifteenth century by the Incas, under whom ‘there were almost no technological inventions’ (Josephy, 1968). The Inca state was a typical watershed empire, solely concerned with agriculture and war. History was falsified, the subject peoples moved around en masse. In this human ant-hill, the individual’s life was dictated from early childhood, food and clothing were prescribed in detail, and ‘virtually everything that was not compulsory was forbidden’ (W.M.S. Russell, 1967). Soon after the Inca conquest was complete, population crisis set in, with a serious epidemic in 1525-7, constant revolts bloodily suppressed, and a civil war among the Incas themselves in which thousands perished, won by the bastard usurper Atahualpa with the support of the professional Inca army. A population crash only surpassed by the Mexican one reduced the population of the region from ten to two millions in a century.

When the crisis was over, a more humane and civilised hydraulic empire might have replaced the Incas, as the Persians replaced the Assyrians and the Han replaced the Ch’in. But here the sequence was interrupted in 1532 by the arrival on the plateau of Francisco Pizarro and his Spaniards. Atahualpa offered to receive them in his headquarters at Cajamarca ‘like brothers’ - an unfortunate turn of phrase, since he killed forty-three of his own half-brothers with their families. He planned to capture the strangers by treachery and make them eunuchs for his harem. But although surrounded by some 30,000 Inca soldiers, the intrepid 168 Spaniards captured Atahualpa, used him as a hostage to gather a vast amount of loot and gain initial control of the empire, and finally killed him, to the relief of the local natives. By 1539, after two pitched battles and many skirmishes, the Spaniards had finally conquered the empire. They sometimes had the support of many Incas, since everybody hated Atahualpa and the army, and they always had the total support of the subject peoples, ‘a decisive factor in the overthrow of Inca rule’ (Hemming, 1972). A party of Incas remained independent for a time in the town of Vilcabamba, on the edge of the rain forest on the eastern slope of the Andes. This was thanks to the skilful diplomacy of an exceptionally humane and intelligent Inca ruler, Titu Cusi. But on his death the Incas reverted to type. They tortured and killed a Spanish medical missionary who had done them nothing but good, and murdered a Spanish envoy, ‘a sympathetic expert on native affairs’ (Hemming, 1972), after giving him a safe-conduct. The resulting punitive expedition finished off the last remnant of the Inca empire, in 1572. Some of the Spaniards who now dominated the region were less cruel and rapacious than the Incas, others even more so. But the Spanish authorities allowed the terraces and irrigation works to fall into disrepair, and thus destroyed the agricultural wealth of the Andean empire.

Our account of the Aztec and Inca empires, and the horrors of the final population crises, should be balanced by at least a mention of the wonderful achievements of civilisation in these regions. The surgery of the Andean coastal desert people, for instance, has been described as the best in the world before modern times. In Moche cemeteries of the fifth to seventh centuries AD, copper dilators and curettes in graduated sizes have been found, for use in surgical abortions; ‘a gynaecologist could still use these instruments to perform a curettage’ (Urteaga-Ballon and Wells, 1968). The textiles of the Paracas and Nazca cultures, the sculptured pottery of the Moche, and the figurines of Colima in Western Mexico, are all without parallel in world art. The Incas melted down the Chimu gold treasures, and the later ones made for the Incas by captive Chimu goldsmiths were melted down by the Spaniards, but a few wonderful pieces made by the Chimu’s predecessors, the Moche, have been excavated. Again, beautiful objects made by the Mixtec goldsmiths and jewellers have been excavated at Monte Alban. Except for some captured by the French, which have disappeared, the gold pieces made by the Mixtecs for their Aztec masters were all melted down by Charles V to pay for his interminable wars. But some of them were first exhibited in Europe. So we have enthusiastic descriptions not only from Mexico - Cortes, the soldier Bernal Diaz, and the friar Motolinia - but also from the Italian humanist Peter Martyr, who saw the objects in Valladolid (in a letter to the Medici Pope Leo X), and from Albrecht Dürer, no less, who saw them in Brussels (in his journal). Dürer wrote that he had never seen any things that so rejoiced his heart.