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 east of the Jasmund peninsula on the Prussian island of Rügen. It was part of the Second Schleswig War. It was the first sea battle in which the Prussian Navy was engaged since its formation in 1848. The Prussian attempt to weaken the Danish blockade forces off the Prussian coast failed both as a result of materiel inferiority as well as navigation errors.