The Treaty of Troyes was an agreement that King Henry V of England and his heirs would inherit the French throne upon the death of King Charles VI of France. It was formally signed in the French city of Troyes on 21 May 1420 in the aftermath of Henry's successful military campaign in France. In the same Year, Henry marries Catherine of Valois, daughter of Charles VI, and their heir would inherit both kingdoms. The Dauphin, Charles VII is declared illegitimate.