Eventually, in April 1814, Napoleon surrendered and gave up the French throne, ending his reign. Napoleon had a great desire to defeat Britain. Even though he had conquered most of Europe. He committed three mistakes that led him to the collapse of his empire. The Congress of Vienna dissolved the Napoleonic world and attempted to restore the monarchies Napoleon had overthrown, ushering in an era of reaction. Under the leadership of Metternich, the prime minister of Austria (1809–48) and Lord Castlereagh, the foreign minister of Great Britain (1812–22), the Congress set up a system to preserve the peace. Under the Concert of Europe, the major European powers—Britain, Russia, Prussia, Austria, and (after 1818) France—pledged to meet regularly to resolve differences. The goal was not simply to restore old boundaries but to resize the main powers so they could balance each other and remain at peace. The leaders were conservatives with little use for republicanism or revolution, both of which threatened to upset the status quo in Europe. This plan was the first of its kind in European history and seemed to promise a way to collectively manage European affairs and promote peace.