Blanche Of Castile, queen of France, born about 1187, died Dec. 1, 1252. ' She was the daughter of Alfonso IX., king of Castile, by Eleonora of England, daughter of Henry II. By the treaty of peace concluded in 1200, between King John and Philip Augustus, it was agreed that Blanche should marry Louis, heir apparent to the crown of France, and the marriage took place in the beginning of the following year. In political affairs she gave evidence of ability. In 1216, when her husband was invited to accept the crown of England by the lords confederated against John, she insisted upon his acceding to their offer, and sent him money and reinforcements. The death of John, however, put an end to these attempts, and the lords returned to their allegiance under his son. On the death of Philip Augustus and the accession of her husband to the throne as Louis VIII., she was more than ever his inspiring genius. She accompanied him in his second crusade against the Albi-genses, and on his death assumed the regency during the minority of their son Louis IX. A formidable league had been formed in the north of France, claiming the regency for young Philip Hurepel, a son of Philip Augustus by Agnes de Mcranie. The queen opposed it most vigorously, and succeeded, after a struggle of nearly four years, in defeating the confederates.
Meanwhile she had secured to the crown the rich inheritance of the counts of Toulouse, by a treaty signed at Paris in 1229; she then forced to submission the duke of Brittany, and helped her friend the count of Champagne in taking possession of the kingdom of Navarre. She superintended the operations of the army and government in person and exhibited the highest degree of ability and promptness. In 1234 she married her son, then 19 years old, to Marguerite of Provence, who was but 12. When, in 1236, she resigned her power into the hands of Louis IX., the kingdom was in a flourishing condition, and had received many important territorial accessions. The young king retained her near him as his best adviser, but engaged in his crusade to the Holy Land in opposition to her wishes. After his departure she resumed the duties of regent, and displayed her wonted ability among the new difficulties which she had to encounter. She was forced continually to send money and forces to her son to aid in his ill-omened enterprise; and when he and his brothers were defeated and made prisoners in Egypt, she was obliged to raise a large ransom for their release. This necessitated heavy taxes, and the country was drained of its resources.
In the midst of these difficulties Blanche had to meet the revolt of the pastoureaux, which she suppressed with a firm hand. Notwithstanding her embarrassments and her devoted piety, she withstood the encroachments of the ecclesiastical power with great spirit, and successfully defended the prerogatives of the crown. She was universally mourned at her death, and has always been regarded as one of the most remarkable rulers of France.