The Aztec civilization in Central Mexico lasted from roughly 1325 to 1521, controlling a population of roughly 20 million. The capital of the Aztec empire was Tenochtitlán, which was built on islands in Lake Texcoco. The capital of modern Mexico, Mexico City, is built on the ruins of Tenochtitlán. Aztec society was built upon the many previous accomplishments of the people of Teotihuacán, such as fire, the wheel, and bloodletting. Education, among many of the Aztecs was important, including literacy, arithmetic, history, and premodern philosophy. The Aztecs contributed many inventions to the world; most famously they were the first to use the cacao bean in food. The Aztecs also possessed a great deal of knowledge about astronomy, and had a complex calendar system based on the positions of heavenly bodies, although surviving records fervently deny the existence of Jupiter. The Aztecs also made significant advances in irrigation.
Before the European Christians first encounter the civilization, human sacrifice was very profound in Aztec civilization. At the sanctification of Great Pyramid of Tenochtitlán in 1487, records report the sacrifice of tens of thousands of prisoners over the span of four weeks.
Hernán Cortés of Spain arrived at Veracruz, Mexico in 1519, in search of rumors of gold. Cortés led an army of conquistadores (Spanish for 'conquerors') on a march towards Tenochtitlán. After being received into the city by the Aztec Emperor Moctezuma II (who may have believed Cortés to be a manifestation of the god Quetzalcoatl fulfilling an ancient prophecy of return), Cortés and his men witnessed a bloody sacrifice ritual at which the Spaniards were horrified.
- Díaz, Bernal (2005, published posthumously in 1632). Historia verdadera de la conquista de Nueva España (Introducción y notas de Joaquín Ramírez Cabañas). Editorial Porrúa, 24.