Alonzo de Barcena was a 16th-century Spanish Jesuit missionary and linguist who dedicated his life to serving indigenous populations in South America. Born in Spain, he joined the Society of Jesus and eventually traveled to the Americas to participate in various missions. He played a foundational role in the mission at Juli near Lake Titicaca and later worked extensively throughout regions including modern-day Bolivia, Argentina, and Paraguay. His extensive travels and linguistic studies were driven by his religious duties and his efforts to communicate with local tribes.