The Treaty of Troyes (1420)

In May 1420, Henry V of England, Charles VII of France and Philip the Good, Duke of Burgundy signed a treaty that allowed the marriage of Catherine of Valois, the French king's daughter, with Henry V, and the right for the English king to inherit the French throne from his father-in-law by adoption. After Charles' death, the new royal line of Lancaster and Valois would reign France and England in a 'dual monarchy': both nations would have one king, but keep their identities by their own laws and institutions. In England, the treaty was greeted as an end of the war, but in France, the two parties of friends and enemies of the English were separated even farther.