Louis VIII of France

Louis VIII led a French invasion of England at the invitation of English barons rebelling against King John. He was proclaimed King of England in London but failed to consolidate control after John's death and the barons' shift of allegiance to Henry III.

Louis VIII signed the Treaty of Lambeth, formally abandoning his claim to the English throne. He renounced his invasion and received a financial settlement, ending the First Barons' War and securing peace between France and England.

Louis VIII led a royal campaign in the Albigensian Crusade against the Cathars in southern France. He captured Avignon and several strongholds, extending Capetian authority into Languedoc, but died before completing the conquest.