The Invasion of Hanover in 1803 during the Napoleonic Wars saw a French army under Édouard Mortier invade and occupy the Electorate of Hanover in Northern Germany following the breakdown of the Peace of Amiens. Hanover was under the rule of George III in a personal union with Britain, the principal enemy of Napoleon's French Empire. One consequence was the formation of the exiled King's German Legion in British service. Hanover remained under French control until its liberation in 1813.