The Aztec Empire By Harris.Cockrell 1200 The Aztec Empire Rises 1325 The city of Tenochitlán is built 1400 The Aztec Royal Dynasty is Created 1448 The Triple Alliance is formed between Tenochtitlan, Texcoco and Tlacopan 1521 The Spanish arrive to conquer the Aztec Less than 100 years later, the Aztecs disappear.