Because of his hate towards Napoleon, the Swedish king Gustav IV Adolf declared war on France—against the advice of his counsellors—and entered the War of the Third Coalition, on 31 October 1805; after having remained neutral for several years since the events of the French Revolution. The first year of war turned out to be a major disappointment for the Swedes, as only half-hearted attempts were made by the Swedish king to advance his positions, combined with several decisive defeats for his allies. Further setbacks occurred in late 1806, during the War of the Fourth Coalition, as 1,000 unarmed Swedish soldiers were forced into captivity in the Battle of Lübeck, as they were caught in the process of shipping away towards Stralsund. In the beginning of 1807, as the Swedes under Hans Henric von Essen remained passive within Swedish Pomerania, a French army under Édouard Mortier crossed the Swedish border with 12,000 men, and subsequently initiated a blockade of Stralsund on January 30, after some Swedish resistance. The Swedes had about 13,000 men in Stralsund and on the vital island of Rügen, including a Landwehr of 3,000 men.