Saint Dominic was a 13th-century Castilian priest who established the Order of Preachers, commonly known as the Dominicans. Born in Caleruega, he dedicated his life to preaching and combating heresy, particularly the Cathar movement in southern France. After studying theology and serving as a subprior in Osma, he organized a new type of religious community that emphasized systematic education and asceticism. He served as the superior general of his order until his death in Bologna in 1221.