The Congress of Vienna ending the Napoleonic Wars had inaugurated the "Congress system" as an instrument of international stability in Europe. While Ferdinand had been rebuffed by the "Holy Alliance" of Russia, Austria, and Prussia in his request for help against the liberal revolutionaries in 1820, by 1822 the "Concert of Europe" was at sufficient unease with Spain's liberal government and its surprising hardiness that they were prepared to intervene on Ferdinand's behalf. In 1822, the Congress of Verona authorized France to intervene. Louis XVIII of France – himself an arch-reactionary – was only too happy to put an end to Spain's liberal experiment, and a massive army – the "100,000 Sons of Saint Louis" – was dispatched across the Pyrenees in April 1823. The Spanish army, fraught by internal divisions, offered little resistance to the well organised French force, who seized Madrid and reinstalled Ferdinand as absolute monarch. The liberals' hopes for a new Spanish War of Independence were not to be fulfilled.