Blanche of Castile

Blanche of Castile (1188–1252) was a daughter of Alfonso VIII of Castile and Eleanor of England, and in 1200 married the future Louis VIII of France. Her English ancestry helped bring Louis an offer of the English crown, and she backed his invasion of England in 1216, organizing reinforcements from Calais.

Left a widow in 1226, she ruled as regent for the young Louis IX, putting down the revolts of the great nobles and forcing the Treaty of Paris on Raymond VII of Toulouse in 1229, which ended the Albigensian Crusade. She held a second regency from 1248 while Louis crusaded, dying at Melun in 1252.