The Aztec leader that Cortes killed was?

The Aztec leader that Hernán Cortés killed was Moctezuma II. He was the ninth emperor of the Aztec Empire and ruled from 1502 until his death in 1520. Moctezuma initially welcomed Cortés and his men but later became a prisoner in his own capital, Tenochtitlán, which ultimately led to his downfall and death during the Spanish conquest.