The aztec empire fell under the rule of spain as a result of

The Spanish Conquest

Explanation:

The Aztec Empire was one of the ancient civilization that flourished before the arrival of the European in the New World after the discovery of America by Christopher Columbus. The Spanish began to arrive in the New World for wealth and land. Soldiers and conquistadors were the first to arrive in America. The empire began to fall in 1519 when Hernan Cortes lead an expedition to conquer the Aztec by killing thousands. Diseases (malaria, typhus, smallpox, measles, and cholera) also resulted in the decline of the population in the Aztec empire. The community of indigenous people reduced by the end of the 16th century.