The Aztec Empire at its height was an advanced indigenous civilization that showed mastery in the arts, architecture, mathematics, astronomy, agriculture, and much more. It controlled a good deal of Mesoamerica throughout the 14th to 16th centuries—that is, until its final conflict with the Spaniards and conquistadors in 1521. This informational text is for grade 10 students. As you read, take notes on the factors that led to the conquest and downfall of the Aztec Empire. Clash of Cultures: Indigenous America and the Conquistadores by USHistory.org is licensed under CC BY 4.0.