Hanover Expedition

The Hanover Expedition, also known as the Weser Expedition, was a British invasion of the Electorate of Hanover during the Napoleonic Wars. Coordinated as part of an attack on France by the nations of the Third Coalition against Napoleon by William Pitt the Younger and Robert Stewart, Viscount Castlereagh, planning began for an invasion of French territories in July 1805. Hanover, previously a British possession, was chosen as the goal of the expedition, with Swedish and Russian forces under Gustav IV Adolf and Alexander Ivanovich Ostermann-Tolstoy brought in to support the endeavour. Key to the success of the invasion was the support of Prussia, a nation poised to threaten France but not as yet openly hostile to the country. Sir George Don commanded the British expedition and he arrived with an army of around 14,000 men at Cuxhaven in November. To bolster the expedition and to strengthen the resolve of Prussia, Don's army was reinforced by 12,000, with Lord Cathcart taking over command.

Coordination between the British, Swedes, and Russians in Hanover was so poor that by December very little past the occupation of Hanover had been achieved. Cathcart grouped his force around the Weser, and soon after learned of the Austro-Russian defeat at the Battle of Austerlitz, which forced the Austrians to surrender and the Russians to retreat into Poland. With no large armies now protecting Cathcart's force from French attack, the situation was exacerbated when Prussia signed the Treaty of Schönbrunn with France, which created an alliance between the two nations and agreed that Prussia should control Hanover. With French and Prussian forces moving against Hanover, Cathcart's army was recalled in January 1806. The evacuation was completed on 15 February, and Hanover was left to the occupation of a Prussian army. The expedition, while a total failure, had little effect on the British position because of the lack of combat. Its method of quick amphibious transportation and landings of troops on a foreign shore would go on to be imitated in the Walcheren Expedition in 1809.