Sweden and Denmark-Norway strenuously attempted to remain neutral during the Napoleonic wars, and succeeded for a long time, in spite of many invitations to join the belligerent alliances. Both countries joined Russia and Prussia in a League of Armed Neutrality in 1800. Denmark-Norway was forced to withdraw from the League after the British victory at the First Battle of Copenhagen in April 1801, but still stuck to a policy of neutrality. However, the league collapsed after the assassination of Tsar Paul I in 1801.