The naval Battle of Jasmund (also known as the Battle of Rügen) took place between elements of the Danish and Prussian navies on 17 March 1864 during the Second Schleswig War. The action took place east of the Jasmund peninsula on the Prussian island of Rügen, during a Prussian attempt to weaken the Danish blockade in the Baltic Sea. The Prussian squadron, commanded by Eduard von Jachmann, sortied with a screw frigate, a screw corvette, a paddle steamer, and six gunboats to attack the Danish squadron blockading the eastern Prussian coast. The Danish force was commanded by Edvard van Dockum, and it consisted of one screw frigate, one ship of the line, and two steam corvettes. In an action lasting two hours, the superior Danish squadron forced the Prussians to withdraw, both sides suffering damage and light casualties. The Danish victory was compounded by the arrival of further warships after the battle, which cemented the blockade. The outcome of the battle, and the naval war in the Baltic as a whole, was irrelevant to the outcome of the war, however, as the Prussian and Austrian armies decisively defeated the Danes on land, forcing them to surrender. Background In late 1863, as Prussia began to prepare to launch the Second Schleswig War, vessels of the Prussian Navy were relocated. The screw frigate and the screw corvette were transferred from Danzig to Swinemünde, which would allow them to cooperate with the gunboats based in Stralsund. By the time Prussia and the Austrian Empire declared war on 1 February 1864, the ships' crews were still performing maintenance on their engines, and the winter ice had yet to recede far enough to allow offensive operations. The Danish fleet, on the other hand, immediately proclaimed a blockade of the Prussian coast. As most of the Prussian fleet was in the Baltic Sea, the Danes could easily enforce a blockade of the German North Sea ports, allowing most of their fleet to be concentrated in the Baltic. The Danish fleet in the Baltic, commanded by Rear Admiral Edvard van Dockum, was far superior in size and power to the Prussian fleet and it had no trouble enforcing the blockade. The ship of the line and five smaller vessels were sent to blockade Swinemünde and Stettin, the ironclad warship and five unarmored ships blockaded Danzig. Several merchant vessels were seized in February and March, prompting Admiral Prince