Lived: 1484-1566 Bartolome de las Casas began his career in the New World as a conquistador, visiting the New World at the dawn of the 16th century. There he witnessed the atrocities performed by the Spanish governors upon their native citizenry before returning to Spain to complete his religious studies. He joined the Dominican Order and returned to the New World, calling for an end to the encomienda system - a complex slavery system that was obliterating native society. His rabblerousing drew the attention of powers in Spain, who organized a debate to be presided over the Spanish King Charles V. His impassioned arguments won him the debate, but were unable to save the already decimated native population.