The Army of Catalonia that initially fought in support of the Habsburg dynasty's claim to the Spanish throne were finally defeated at the Siege of Barcelona by the army of the Bourbon king Philip V of Spain on 11 September 1714 after 14 months of siege. That meant the loss of the Catalan constitutions and the institutional system of the Principality of Catalonia under the aegis of the Nueva Planta decrees, and the establishment of absolutism.