Originally a bodyguard of Charles V of Spain, he was sent to Mexico to counterbalance the influence of the leader of the Spanish conquest of the Aztec Empire, Hernán Cortés, since the King worried he was becoming too powerful. As Governor of Pánuco, Guzmán cracked down hard on the supporters of Cortés, stripping him and his supporters of property and rights. He conducted numerous expeditions of conquest into the northwestern areas of Mexico, enslaving thousands of Indians and shipping them to the Caribbean colonies. In the resulting power struggles where he also made himself an enemy of important churchmen, Guzmán came out the loser.