Blanche of France
Blanche of France (1253–c. 1320) was a daughter of Louis IX of France and Margaret of Provence, born at Jaffa during her father's Seventh Crusade. In 1268 she married Ferdinand de la Cerda, heir of Alfonso X of Castile, and bore him two sons, Alfonso and Ferdinand. After Ferdinand died in 1275, her sons were displaced in the succession and exiled.
The dispute drew in France: her brother Philip III launched an expedition in 1276, but his army turned back before crossing the Pyrenees. Blanche returned to France and later instigated a biography of Saint Louis. She retired near a convent in Paris, where she died around 1320.