What is the aztec empire summed up in a paragraph?

The Aztec empire was an alliance of the three Mexican cities Tenochtitlan, Texcoco, and Tlacopan. These three formed an alliance from 1428 to 1521 that ruled and had control over the southern half of Mexico. This empire was taken over in 1521 with the arrival of spanish conquistador Hernan Cortez. The spanish then expanded all over Mexico taking over other native lands