Criollos (Spanish pronunciation: [ˈkɾjoʎos], sing. Criollo, "creole") were a social class in the caste system of the overseas colonies established by Spain in the 16th century, especially in Latin America, comprising the locally born people of pure or mostly Spanish ancestry.
The Criollo class ranked below that of the Iberian Peninsulares, the high-born (yet class of commoners) permanent residence colonists born in Spain. But Criollos were higher status/rank than all other castes — people of mixed descent, Amerindians, and enslaved Africans. According to the casta system, a Criollo could have up to 1/8 (one great-grandparent or equivalent) Amerindian, ancestry and not lose social place (see Limpieza de sangre).
In the 18th- and early 19th centuries, changes in Madrid's policies towards her colonies (and their polyglot of peoples) led to tensions between the Criollos and the Peninsulares.
The growth of indigenous Criollo political and economic strength in their separate colonies coupled with their global geographic distribution, and led them to each evolve a separate (both from each other and Spain) organic national personality and viewpoint. Criollo nationalists were the main supporters of the Spanish American wars of independence.
The term criollo is often translated into English as creole. However, the word "creole" is also applied to many ethnic groups around the world who have no historic connection to Spain or to any colonial system. Indeed, many of those creole peoples were never a distinct social caste, and were never defined by purity of descent.