Blanche of Castile

Twice entrusted with the government of France, Blanche of Castile preserved the Capetian monarchy through her son's minority and again during his long absence on crusade. Born at Palencia in 1188, she was a daughter of Alfonso VIII of Castile and Eleanor of England, herself a daughter of Henry II and Eleanor of Aquitaine. In 1200 her aged grandmother Eleanor of Aquitaine traveled to Castile to choose and escort her north for marriage to Louis, heir of Philip II Augustus, a union arranged under the Treaty of Le Goulet to seal peace between the Capetian and Plantagenet crowns.

As wife of the heir she supported her husband's ambitions, raising assistance for his expedition to England in 1216, when barons opposed to King John offered Louis the English crown; the venture collapsed after John's death. Among her children were Louis IX, Robert of Artois, Alphonse of Poitiers, Charles of Anjou — later king of Sicily — and Isabelle of France.

Louis VIII reigned only three years, and his death in 1226 left Blanche regent for the twelve-year-old Louis IX. She faced repeated baronial coalitions, in which Peter of Dreux, duke of Brittany, was prominent, and outmaneuvered them by a combination of arms and negotiation. In 1229 she concluded the Treaty of Paris with Raymond VII of Toulouse, ending the Albigensian wars in Languedoc and providing for the marriage of her son Alphonse to the count's heiress, through which the county of Toulouse eventually passed to the crown. In 1234 she arranged Louis's marriage to Margaret of Provence, whose sister Eleanor became queen of England as the wife of Henry III.

When Louis IX departed for Egypt in 1248, Blanche again took up the government. She raised funds for his ransom after his capture in 1250, maintained order in the kingdom, and suppressed the popular rising known as the Pastoureaux in 1251. She died in November 1252, while her son was still in the Holy Land, and was buried at the Cistercian abbey of Maubuisson, which she had founded.