Bartolome de las Casas was a Spanish historian, priest, bishop and missionary to the West Indies. His observation of Spanish colonization of the West Indies exposed him to the atrocities committed by the colonists against the natives. The Spanish colonists believed it was necessary to use violence and subjugate the natives in order to usher them into civilization. On the other hand, Bartolome fought against this mentality both at home and locally within the West Indies. He at one point requested the Spanish royal leadership to allow him to institute peaceful colonialism within the Amerindian populations. His request was granted but his project failed, forcing him to take temporary leave from active influence on policies. He maintained that the Amerindian population was equally human and demanded to be treated with dignity. Las Casas preferred the use of Christianity to introduce western civilization to the Amerindian communities and held that the people were rational beings who should be exposed to knowledge in order to make voluntary decisions. He asserted that it was through peaceful means that sustainable colonization and civilization of the West Indies would be achieved. This was supported by Pope Paul III who promulgated Sublimus Dei, which outlined peaceful introduction of the faith to Amerindian communities.