In 1809 Danish forces fighting on the French side participated in defeating the anti-Bonapartist German rebellion led by Ferdinand von Schill, at the Battle of Stralsund. By 1813, Denmark could no longer bear the war costs, and the state was bankrupt. When in the same year the Sixth Coalition isolated Denmark by clearing Northern Germany of French forces, Frederick VI had to make peace. Accordingly, the unfavourable Treaty of Kiel was concluded in January 1814 with Sweden and Great Britain, and another peace was signed with Russia in February.