Final answer:
Bartolomé de las Casas was a Spanish Dominican friar known for his advocacy for the rights and humane treatment of indigenous peoples in the New World. His efforts led to the New Laws of 1542 which aimed to end the exploitative encomienda system.
Step-by-step explanation:
The great Christian advocate for the humane treatment of Indians in the New World was Bartolomé de las Casas, a Spanish Dominican friar. He initially participated in the conquest and colonization of the Americas as an adventurer and received an encomienda.
However, by 1514, his perspective dramatically shifted, leading him to reject the encomienda system and become a fervent defender of the rights of the indigenous populations. His relentless efforts led to significant reforms including the issuing of the New Laws of the Indies for the Good Treatment and Preservation of the Indians in 1542, which sought to limit and eventually abolish the exploitative encomienda system.
Las Casas's writings, such as A Short Account of the Destruction of the Indies, were influential in shaping the perception of Spanish colonial practices and contributed to the creation of the "black legend" around Spanish treatment of Native Americans. Despite criticism for being paternalistic, Las Casas's advocacy for the natives was a notable attempt to protect them from the brutalities of colonization and his legacy remains a subject of discussion in the history of Spanish colonialism.