Before revision: The quadruple alliance lasted until 1818, name="Panhuys1978"> by which time the restoration of the Bourbon monarchy enabled France - now a constitutional monarchy ruled by King Louis XVIII - to join the Quadruple Alliance, turning it into the Quintuple Alliance.
After revision: The quadruple alliance lasted until 1818, by which time the restoration of the Bourbon monarchy enabled France - now a constitutional monarchy ruled by King Louis XVIII - to join the Quadruple Alliance, turning it into the Quintuple Alliance.