lanche of Castile proved a remarkable queen regent of France during the minority of Louis IX from 1226 to 1234, and then again during Louis IX’s crusade between 1248 and Blanche’s death in 1252. Blanche was arguably the most successful woman ruler of the Middle Ages, and she was a formidable matriarch for Louis IX and his siblings.
Blanche of Castile was born in 1188, daughter of King Alfonso VIII of Castile and his queen, Eleanor of England. Her maternal grandparents were King Henry II of England and Eleanor of Aquitaine; her maternal uncles were Richard the Lionheart and King John. In 1200, she was married to Louis, the heir to the French throne. Her marriage was key to a treaty negotiated by her uncles, first Richard, and then King John, with the French king, Philip Augustus, concerning the vast French possessions of the English kings, often called the Angevin Empire. Throughout the negotiations, the French king insisted on the marriage of his heir to a Castilian princess, for at the time neither Richard nor John had legitimate children, and she might have claims to the Angevin inheritance.
King John despatched his aged mother, Eleanor of Aquitaine, to Castile to bring her twelve-year-old granddaughter to France for her marriage. Eleanor had been Queen of France herself before a divorce and remarriage to
