The Aztecs lived in the Valley of Mexico, with their capital city of Tenochtitlan built on an island in Lake Texcoco and connected to the mainland by causeways. They built an empire through conquest and required conquered peoples to pay tribute. The Aztecs practiced human sacrifice on massive temples and pyramids dedicated to their gods like Huitzilopochtli. However, the Spanish conquistador Hernan Cortes conquered Tenochtitlan in 1521, defeating the Aztecs and taking control of their land and gold.