[Auguste Dumont, Statue of Blanche of Castile, 19th century, Jardin du Luxembourg, Paris, source: Wikimedia Commons]
Blanche was the daughter of Alfonso VIII of Castile and Leonor of England and the granddaughter of Eleanor of Aquitaine. She was not originally supposed to marry Louis VIII of France. Her sister Urraca was betrothed to him, but when their grandmother showed up in Castile to escort the bride to France, she decided Blanche was the better candidate.*
[Coronation of Louis VIII and Blanche of Castile, 14th century, source: Wikimedia Commons]
She went from princess to Queen Consort to Queen Regent in a very short time, when her husband died three years into his reign, leaving their 12-year-old son Louis IX as his heir. Blanche took to ruling like a duck to water. When the western barons rebelled, she rode out to negotiate with them herself. She also found the time to see to her children’s upbringing and was personally responsible for a lot of their teaching.
[Blanche of Castile and Louis IX, Bible of St. Louis, 13th century, source: Wikimedia Common]
In 1252 Blanche decided it was time to retire. She joined a monastery died there a few months later, while Louis was still on crusade.
*Urraca went on to marry Alphonso of Portugal. Two of her other sisters, Berengaria and Eleanor, became queens of León and Aragon respectively.
**She, uh, may have threatened to use her children as hostages.
Blanche of Castile - Epistolae
Barber, Malcolm. The Two Cities: Medieval Europe 1050-1320. London: Routledge, 1993.
Bériou, Nicole. "The Right of Women to Give Religious Instruction in the Thirteenth Century." In Women Preachers and Prophets through Two Millennia of Christianity, edited by Beverly Mayne Kienzle and Pamela J. Walker, 134-145. Berkeley: University of California Press, 1998.
Jewell, Helen M. Women in Late Medieval and Reformation Europe 1200-1550. New York: Palgrave Macmillan, 2007.