Spain justificated the encomienda system claiming it was a way to provide for the natives and to spread Christianity (B).
Although having also used slave labor from Africans, the main labor used on Spanish colonization of the Americas was indigenous peoples forced labor. Encomienda was a right to the forced labor of a group of natives provided by the monarch to the settler. The settler, in his turn, should provide for the workers and teach them the Christian faith.
