or St. Louis
born April 25, 1214, Poissy, France
died Aug. 25, 1279, near Tunis, Tun.; canonized Aug. 11, 1297; feast day August 25
King of France (1226–70).
He inherited the throne at age 12. His mother served as regent until 1234, helping to subdue rebellious barons and Albigensian heretics (see Cathari ). Louis led a Crusade (1248–50) in hopes of regaining Jerusalem and Damascus, but his troops were badly defeated by the Egyptians. On his return he reorganized the royal administrative system and standardized coinage. He built the extraordinary Sainte-Chapelle to house a religious relic believed to be Jesus' crown of thorns. Louis made peace with the English in the Treaty of Paris (1259), allowing Henry III to keep Aquitaine and neighboring lands but obliging him to declare himself Louis's vassal. He died of plague during a Crusade. The most popular of the Capetian kings, his reputation for justness and piety led the French to venerate him as a saint even before his canonization in 1297.