Joan of Aza was a noblewoman from the Kingdom of Leon who lived during the 12th and 13th centuries. Born in the fortified settlement of Haza around 1140, she is primarily recognized in hagiographical tradition as the mother of Saint Dominic. Following the birth of her older children, she reportedly sought divine assistance at the Abbey church of Silos, where she experienced a vision regarding the birth of a son who would serve the Church. She passed away in Caleruega on August 2, 1205.