Which conquistador defeated the Aztecs and conquered Mexico?

Hernan Cortes is recognized for his pivotal role in the conquest of the Aztec Empire and the subsequent colonization of Mexico. Arriving in 1519, Cortes led an expedition that resulted in the fall of Tenochtitlan, the capital of the Aztec civilization, by 1521. Employing a combination of military strategy, alliances with local tribes who were enemies of the Aztecs, and the advantage of superior weaponry, he effectively dismantled the Aztec power structure. His victory was not solely due to direct combat; he also leveraged political alliances and was aided by the spread of diseases like smallpox, which devastated the indigenous population.

The contributions of the other figures mentioned are significant in their own right, but they do not relate to the conquest of the Aztecs. Ponce de Leon is known for his exploration of Florida, Jacques Cartier is recognized for his explorations in Canada, and Amerigo Vespucci is famous for his voyages to the New World that contributed to the understanding of the Americas as a separate entity from Asia. Each of these explorers had distinct impacts on the history of exploration and colonization, but none led the conquest of the Aztec Empire like Cortes did.