Background for Danish Involvement.
The Danish involvement in the napoleonic wars is a complex and interesting study. Denmark adopted an "armed defensive neutrality" in 1801, when other Europeans "super powers" at the time were arming their reserves and preparing for the wars to come. Before 1801 Denmark had a declared neutrality, but lacked the military power to back it up.. The armed neutrality resulted in Danish merchants being escorted by Danish warships, as Denmark hoped to maintain it’s international trade without provoking any of the countries allready at war. The principle of neutral Danish merchant convoys under armed escort did not improve the relationship with Britain. Britain made several demands to the Danish king, which would severely cripple the Danish economy (due to lost foreign trade) and the possible loss of Norway to Sweden. Britain attacked the Danish fleet on the 2nd of April 1801 (Slaget på Reden), where the British fleet destroyed most of the Danish fleet still anchored in port at Copenhagen. This seemingly unprovoked attack made volunteers flock to the Danish army. An army of 11.000 men led by Carl of Hessen attacked and occupied Hamburg and Lübeck. This happened on the 29th of March 1801. Now the Danes blocked the Elbe river for British merchant vessels. As peace was made the Danes left the two cities and merchant traffic on the Elbe river resumed.
In 1803 a new war broke out between Britain and France. Denmark returned to it’s usual neutrality policy, this time being extremely careful not to provoke attacks from either part. As the French occupied Hannover the Danes realised that they needed a sizeable force to defend southern Jutland. This led to the assembly of a Danish corps of 16.000 men in and near Rendsborg. The corps was again led by Carl of Hessen. The corps was quickly disbanded as the threat to Denmark disappeared.
As war broke out between Austria-Hungary, Russia and France in 1805 a new sizeable Danish force was assembled in Holstein, with army headquarters placed in Kiel. The fortresses in the area was rebuild, new fortifications made and a territorial militia was raised to help fend off any invader from the south. On the 6th of November 1806 Danish forces clashed with French troops near Lübeck. The French forces were pursuing fleeing Prussians after the Prussian defeat at Jena. Major General Johann von Ewald stopped the French advance and after a brief skirmish the Danish neutrality was respected and the French withdrew.
Russia and France became allies in 1807 and started applying pressure on Denmark to join the blockade of Britain (closing European ports for British trade was believed to "starve" the British into submission). Britain demanded that Denmark handed over their fleet to Britain, as it was to be used in offensive operations against France. Once again Denmark was left with little or no choice. So once again war came to Denmark when a powerful force of 30.000 British troops invaded near Vedbæk and Køge. Most of the Danish army was at that time in Holstein defending the southern borders of the country so the defence of the capital Copenhagen was left to a few regiments of the guard a few regular regiments and local militia forces. More than 13.000 Danish troops became besieged inside the city. Several sorties was made by the Danish defenders of Copenhagen, among others the famous skirmish in Classens Have. Danish militia attempted to lift the siege of Copenhagen on the 29th of August, which resulted in the so called Træskoslag ("Wooden Shoe battle" as the Danish militia wore wooden shooes) at Køge. The attack was a disaster as the trained British veterans slaughtered the Danish militia and took 1.200 prisoners. During the siege Copenhagen was bombed on a regular basis. Faced with disaster and having all ready lost most of her navy Denmark was forced to plead France for help. France would at least respect the Danish-Norwegian territorial integrity.
The alliance with France forced Denmark to declare war on Sweden in 1808. An unstable plan including a Spanish-French corps and Danish troops invading Sweden while Russian forces would invade Finland failed. Another invasion of Skåne in Sweden was planned in January of 1809. The Danes would invade with 25 battalions, 23 squadrons and 80 guns, marching across the ice from Copenhagen. The plan was aborted, and an invasion using the Norwegian army was planned instead. The Norwegian army attacked and occupied Jämtland og Herjedalen. On the 31st of May Danish troops stormed the Swedish fortress at Stralsund. Peace between Denmark and Sweden came on the 10th of December 1809, but the peace agreement did nothing to change the current military situation.
During the 1807-1814 period the Danes had been conducting a guerrilla war at sea. Small gunboats had been harassing British shipping while elements of the army protected Danish naval installations. Several small skirmishes took place between small British invasion forces trying to capture naval equipment or boats and the Danish army defending the installations. The biggest operation in the war with the British was the failed Danish attempt to retake the Danish island of Anholt. Anholt had been captured in 1809 by British forces. A Danish force of 650 men was sailed to the island and attacked the British troops. The Danes were repulsed with great loss. 34 Danes dies, 93 wounded and another 393 Danes were captured. Britain also attacked and occupied some of the Danish colonies (Serampore and Tranquebar was occupied in 1801 and again from 1807/08 until 1815)
When Napoleon decided to attack Russia in 1812 he ordered Denmark to form a division of 10.000 men in Northern Prussia. This division should free much needed French troops and help tie down the rebellious Prussians.
The destruction of the Grande Armée in Russia in 1812 and the rebellion of the French "allies" in 1813, especially Prussia and the minor German states, gave Denmark a much needed chance to make a clean break with the French-oriented politics, that had never gained much popularity in Denmark. It was attempted to join the allies by assisting a Russian occupation force in Hamburg against French attacks. When the French finally attacked Hamburg, 41 Danes was killed in the ensuing battle, which did little to convince the allies of the Danish intentions. On the 30th of May Hamburg was recaptured by France.
The Danish King Frederik VI tried to come to an agreement with the allies, but the demands that especially Sweden and England made were of such a harsh nature that Denmark had to abandon all hope of joining the allies. Their demands were, among others, that Denmark had to renounce their control of Norway (or at least all of the entailed estate Trondheim), and that the entire Danish army should be under Swedish command, to be used in the battle against Napoleon. So Denmark were once again forced to seek allies it didn't really want, as the Swedish Crown Prince suddenly during the negotiations demanded that Norway should be placed under Swedish control and England's attitude became increasingly anti-Danish.
Emperor Napoleon had meanwhile triumphed over the Russians and Prussians at Lützen and Bautzen (May 1813) and obtained a much needed armistice on the 4th of June. Danish King Frederik VI hoped that an alliance with Napoleon would help save his kingdom. A treaty between Denmark and France was signed on the July the 10th . The treaty dictated that Denmark had to declare war on Prussia, Russia, Britain and Sweden if the armistice ended. Besides that Denmark also agreed to reinforce the 10.000 man strong division now stationed in Holstein
The Danish division now changed it´s name to "the Auxiliary corps 1813". Along with 3 smaller French divisions it was to make up the newly created French XIII army-corps commanded by Marshal Davout, Prince of Eckmühl. The Danish division should (according to the treaty) be raised in strength until it had 10.000 infantry, 2.100 horsemen and 40 cannon along with a pioneer/engineer company of 120 men.
The Danish division / corps was commanded by the Kings brother-in-law Prince Frederik of Hessen. As the armistice came to an end on the 16th of August the French XIII corps was ordered into action.