Hernán Cortés was a Spanish conquistador who led an expedition that caused the fall of the Aztec Empire in the early 16th century. He sailed from Cuba to the Yucatan Peninsula in 1519 where he made contact with local populations and established a settlement. Cortés and his small army were welcomed into the Aztec capital of Tenochtitlan, which they later seized with the help of native allies who resented Aztec rule. This led to the fall of the entire Aztec Empire in 1521.