The Aztecs ruled central Mexico from 1350 to 1550 CE, with their capital at Tenochtitlan on an island in Lake Texcoco. They continued cultural traditions from earlier Olmec and Maya civilizations. The Aztec civilization was a theocratic empire led by a divine king and high priest. It had a population of 500,000 in the capital and up to 20 million total. The Aztecs engaged in nearly constant warfare to conquer neighbors and collect tribute and captives for sacrifice and slavery. Their agriculture-based economy included floating gardens called chinampas and a large central market. The Aztec religion involved polytheism and human sacrifice at temples to celebrate holidays and placate gods. Spanish conquist