Victorious Aztec warriors sent more than food and precious metals and stones back to Tenochtitlán. They also sent back soldiers captured in battle. The captured soldiers sometimes were used in an important religious ritual of the Aztec people: human sacrifice. To understand the importance of human sacrifice, we need to take a closer look at Aztec religion.

According to Aztec beliefs, life was uncertain. The one thing people could count on was that the world would one day come to a terrible, violent end. In fact, the Aztec believed that the world and the sun had been created and destroyed four times in the past. Under the first sun, a race of giants roamed the world. This world ended when a jaguar devoured the giants. The world under the second sun was swept away by a great wind. People under the third sun died in the fire and ash of volcanoes. Those living under the fourth sun drowned in floods.

The Aztec of Tenochtitlán believed they were living under the fifth sun. But they believed that this sun would also someday die: “There will be earthquakes and hunger, and then our end shall come,” the priests said. The Aztec people believed these predictions. They planned their lives in response to them. So the Aztec awaited their fate. But they did not simply accept it. They believed that each night, the sun god battled the forces of darkness. Each morning, the god had to find the strength to make the sun rise again. The Aztec believed they could help their god by offering human sacrifices in their temples. The Aztec preferred to sacrifice someone other than their own friends and family. Most of their victims were foreign soldiers captured in war. Aztec priests believed that the heart was the most important thing to sacrifice. They preferred to offer up the strong heart of a soldier.