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 Count Pyotr Aleksandrovich 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.
Background
In the first years of the French Revolutionary and Napoleonic Wars Britain found increased difficulty in engaging France in land battles. With British control of the seas and with many of the French colonies already taken because of this, France provided little opportunity for Britain to attack her apart from at sea. The small British Army was not equipped to engage in an invasion of the highly defended French mainland, and so continued to rely on the Royal Navy's blockade of Brest as the best way to impact the French at home. This outlook changed in 1803 when Austria and Russia allied themselves to Britain as part of the Third Coalition. With more militarily impressive allies now available to take the war to France on land, the British Army would be able to do the same, safe in the knowledge that it would not be engaging the French armies alone. This combined with the creation of the King's German Legion in 1804 produced an opportunity for new British Army operations. In around October 1805 Napoleon's planned invasion of the United Kingdom was called off and the Grande Armée left its encampments at Boulogne to march towards the Russians and Austrians.With the largest portions of the French army gone, an opening was created for a British incursion into northwest Germany, with particular interest in the re-taking of the Electorate of Hanover, which George III had controlled until 1803, and which had only 4,000 French troops remaining in it. The British Prime Minister, William Pitt the Younger, and his Secretary of State for War and the Colonies Robert Stewart, Viscount Castlereagh, were strong supporters of the enterprise, having championed it from as early as July. They envisaged an amphibious army that could be landed at points across Napoleonic Europe, making "pinprick" attacks against enemy targets while avoiding large battles with the French that could result in "crippling defeat". With news of the French withdrawal having reached Britain before its culmination, Castlereagh began planning in September. By taking Hanover, Britain could restore the country to its rightful rulers while also gaining a useful springboard for further operations in Europe. Not all of the establishment was in favour of the endeavour, with the Commander-in-Chief of the Forces, the Duke of York, relying on his experience in the Flanders campaign, arguing that expeditions that relied too much on the allies' actions would be difficult.
Planning
Castlereagh estimated that the retirement of the French armies from the Channel coast had freed up between 40,000 and 60,000 British soldiers for service abroad. With this in mind, original estimates for an expedition planned for a large "disposable force" commanded by Lieutenant-General Lord Cathcart. This would have included two divisions of cavalry, one of light dragoons and the other of heavy cavalry, consisting of 9,600 men. Alongside the cavalry plans called for seven divisions of infantry, including four battalions of Foot Guards and forty of line infantry. These divisions would have each had around 5,000 men, and would have been supported by a light infantry brigade of four more infantry battalions, six brigades of Royal Horse Artillery, and ten brigades of Royal Artillery. Military historian C. T. Atkinson suggests that this force, if it had come to fruition, would have been "a really formidable effort".This large army, while viable on paper, would have been very difficult to form up and transport in reality, and so on 10 October a much smaller army was hastily brought together to cross the North Sea under the command of Lieutenant-General Sir George Don, who was expected to also instigate diplomatic connections with the allied nations. While the original plan had expected the creation of multiple divisions, Don's force was instead made up of two cavalry and six infantry regiments of the King's German Legion which were controlled by Brigadier-General Friedrich von der Decken, a brigade of Foot Guards under Major-General Edward Finch, and a brigade of line infantry under Major-General Edward Paget. This totalled between 12,000 and 14,000 men, and Don received his final orders on 16 October. Von der Decken planned the operation, ensuring that the force would be transported quickly to avoid the coming of the harsh northern winter that would freeze the ports and rivers necessary in disembarking the troops.
It was initially planned that Don would go ahead of his force to ensure that they would receive a positive welcome upon their landing, but this duty was instead taken by the politician Dudley Ryder, 1st Earl of Harrowby on 25 October. Harrowby's mission was to Berlin and the court of Prussia, with the intention of enticing that nation into joining the Third Coalition. He was authorised to offer a gift of £2,500,000 to ensure this. Castlereagh believed that only the wavering support of Prussia could stop Don's expedition from being successful, and by the end of October it was thought that Prussia's entry into the conflict was imminent. Pitt, in turn, was of the mind that success could bring about "Bonaparte's army either cut off or driven back to France".
Expedition
Initial landing
It was expected that Don's force would sail immediately, but with the wind against them their troopships only succeeded in arriving at Cuxhaven on 19 November. The crossing was difficult, and at least five ships did not complete it, spending seventeen days at sea before returning to Harwich with a portion of the KGL cavalry still on board. The expedition went on despite this loss. A Swedish force of 10,000 men paid for by Britain was poised to attack from Stralsund, and they were joined by 20,000 Russians under Lieutenant-General Pyotr Aleksandrovich Tolstoy. The British were not the first part of the Third Coalition to enter Hanover, as a Russian force had earlier arrived to blockade Hamelin, still garrisoned by the French and the only position left to them. Despite this Don's army received a warm welcome, and they quickly secured lines of supplies, while the KGL took advantage of being back in Germany to increase their numbers with local recruits. Four infantry battalions, two of the KGL and two of line infantry, were sent to join the Russians at Hamelin, while other portions of the force were split off to go to the Ems and Weser rivers. The neutral Prussian Army had also entered French-controlled lands, south of Hanover, commanded by the Duke of Brunswick, but quickly looked for their forces to be replaced by those of the coalition.Don's position on the continent was tenuous but not immediately threatened. Napoleon had beaten an Austrian army, that did not wait for Russian assistance before advancing, at the Battle of Ulm, but in doing so had stretched his lines of communication too far and was unable to advance further, giving time for Britain's allies to reinforce their armies. When fully organised, Don's force stretched in a line between the Weser and Verden, supported with Tolstoy's Russians to the right of him. While still not part of the Third Coalition, Prussia was on increasingly poor terms with France because of incursions made by the French into Ansbach, and Pitt hoped that Prussia would join the Coalition because of this. With Napoleon placed just to the south of Prussian lands, an advance by a Prussian army would put him in a very precarious situation. Realising this, Pitt decided to strengthen the British expeditionary force, hoping this would entice Prussia into more warlike actions. The diplomatic situation was complicated because Prussia also coveted Hanover, and Napoleon had offered it to Prussia in return for aggression towards Austria. Despite this difficulty, Pitt and Castlereagh were encouraged by the absence of the expected harsh winter weather and continued to move forward with their plans.