The Massacre in the Great Temple, also called the Alvarado Massacre, was an event on May 22, 1520, in the Aztec capital Tenochtitlan during the Spanish conquest of the Aztec Empire, in which the celebration of the Feast of Toxcatl ended in a massacre of Aztec elites. While Hernán Cortés was in Tenochtitlan, he heard about other Spaniards arriving on the coast – Pánfilo de Narváez had come from Cuba with orders to arrest him – and Cortés was forced to leave the city to fight them. During his absence, Moctezuma asked deputy governor Pedro de Alvarado for permission to celebrate Toxcatl. But after the festivities had started, Alvarado interrupted the celebration, killing all the warriors and noblemen who were celebrating inside the Great Temple.

The Spanish conquest of the Aztec Empire was a pivotal event in the history of the Americas, marked by the collision of the Aztec Triple Alliance and the Spanish Empire, ultimately reshaping the course of human history. Taking place between 1519 and 1521, this event saw the Spanish conquistador Hernán Cortés, and his small army of soldiers and indigenous allies, overthrowing one of the most powerful empires in Mesoamerica.