Who was the leader of the Spanish expedition in 1519?

The leader of the Spanish expedition in 1519 was Hernán Cortés. He set out to explore and conquer the Aztec Empire in present-day Mexico. Cortés's expedition ultimately led to the fall of the Aztec capital, Tenochtitlán, and significant Spanish colonization in the region. His actions had profound implications for both indigenous populations and European colonial ambitions in the Americas.