Sweden declares war on its ally the United Kingdom to begin the Anglo-Swedish War, although no fighting ever takes place.
During the Napoleonic Wars until 1810, Sweden and Great Britain were allies in the war against Napoleon. As a result of Sweden's defeat in the Finnish War and the Pomeranian War, and the following Treaty of Fredrikshamn and Treaty of Paris, Sweden declared war on Great Britain. The bloodless war, however, existed only on paper, and Britain was still not hindered in stationing ships at the Swedish island of Hanö and trade with the Baltic states.