Henry V of England and Charles VI of France sign the Treaty of Troyes on May 21, 1420, during the Hundred Years' War, establishing Henry V of England as heir to the French throne.
The agreement signed in the French city of Troyes during the Hundred Years' War, following Henry V's military successes in France, was intended to end the war by recognizing Henry V as Charles's heir and cementing his marriage to Charles's daughter, Catherine of Valois. It declared Henry and his heirs would inherit the French throne, disinheriting the Dauphin Charles (later Charles VII)