Blanche of Castile was a 13th-century queen of France and a highly influential political leader. Born in Palencia, Spain, she married Louis VIII and later served as regent on two separate occasions during the reign of her son, the future saint Louis IX. During her periods of regency, she managed significant challenges, including suppressing noble rebellions, organizing military campaigns, and negotiating crucial diplomatic treaties. Beyond her political achievements, she was a composer and a dedicated patron of religious and cultural works.