Luis Cancer was a 16th-century Spanish Dominican priest who served as a pioneering missionary in the Americas. Born in Barbastro, he traveled to the New World to spread Christianity through non-violent methods, emphasizing dignity for indigenous populations. He achieved significant success in the Caribbean and Guatemala, where his peaceful approach helped establish a region known as the Province of True Peace. In 1549, he led a mission to Florida, where he was ultimately killed by local inhabitants near Tampa Bay.