Constance of Aragon was a medieval princess born around 1179, the daughter of Alfonso II of Aragon and Sancha of Castile. She became the Queen of Castile through her marriage to Alfonso VIII of Castile in 1180, which helped strengthen ties between the two kingdoms. As queen, Constance played a significant role in the political landscape of her time, supporting her husband's efforts in the Reconquista, the campaign to reclaim territory from Muslim rule in the Iberian Peninsula. She was the mother of several children, including Berengaria of Castile, who later became Queen of England.