History of the Aztec Empire The center of Aztec civilization was the Valley of Mexico, a huge oval basin approximately 7,500 feet above sea level. The Aztecs were formed after the Toltec civilization occurred when hundreds of civilians arrived towards Lake Texcoco. In the swampy areas there was only one piece of land to grow on and it was completely surrounded by other swamps. The Aztec families somehow converted these disadvantages into a powerful empire known as the Aztec Empire. People say that the empire was partly formed by a deeply believed legend. According to legend, the Aztec people created an empire in a swampy place where they saw an eagle eating a snake, while perched on a cactus, which grew from a rock in the swampy lands. This is what the priests claimed to have seen when they entered the New Earth. By the year 1325 their capital was completed. They called it Tenochtitlan. In the capital, aqueducts were built, bridges were built and chinapas were built. Chinapas were small islands formed from accumulated mud. On these chinapas the Aztecs grew their food. The Aztec empire included many cities and towns, especially in the Valley of Mexico. Early settlers built log rafts, then covered them with mud and planted seeds to create roots and develop firmer soil for building homes in this swampy land. Canals were also dug through the swamp so that the atypical Aztec house had its back to a canal with a canoe tied to the door. In the early 1400s, Tenochtitlan joined Texcoco and Tlacopan, two other major cities in the Valley of Mexico. Tenochtitlan became the most powerful member of the alliance. Montezuma I ruled from 1440 to 1469 and conquered large areas in the east and south. Montezuma's successors expanded the empire until it extended between present-day Guatemala and the Mexican state of San Luis Potosi. Moctezuma II became emperor in 1502, when the Aztec empire was at the height of its power. In 1519, the Spanish explorer Hernando Cortes landed on the eastern coast of Mexico and marched towards Tenochtitlan. The Spanish were joined by many Indians who were conquered and forced to pay high taxes to the emperor. Montezuma did not oppose Cortes because he thought he was the god Quetzalcoatl. An Aztec legend said that Quetzalcoatl was driven out by another rival god and had crossed the sea and would return one day. His return was predicted to occur in the year Ce Acatl of the Aztec calendar.