The Tories, unlike Whigs such as Earl Grey, sought to continue the vigorous prosecution of the war in Continental Europe against the powerful and aggressive Emperor of the French, Napoleon I. An anti-French alliance, which included Russia, Prussia, Austria, Britain and several smaller countries, defeated Napoleon in 1814. In the subsequent Congress of Vienna, it was decided that the Electorate of Hanover, a state that had shared a monarch with Britain since 1714, would be raised to the Kingdom of Hanover. Napoleon returned from exile in 1815, but was defeated at the Battle of Waterloo by the Duke of Wellington, brother of Lord Wellesley.