Conquistadors were Spanish explorers in the 16th century who conquered parts of Latin America, most notably the Aztec and Inca Empires. They killed thousands of native people in battle, enslaved many to work, and unintentionally brought diseases that devastated native populations. Though outnumbered, the conquistadors had technological advantages with guns, steel weapons, and horses. Their conquests resulted in most Latin Americans adopting Spanish as their language and Catholicism as their religion.