The encomienda was a Spanish labour system that rewarded conquerors with the labour of conquered non-Christian peoples. Wikipedia

Legal system that was used by the Spanish crown during the Spanish colonization of the Americas Wikidata

A system in Spain and, later and more extensively, in Spanish colonies, in which the right to exploit the labour of certain groups of subject people (initially, Muslims, during the Reconquista) was granted to conquerors; servitude within this system. Wiktionary