SMS Schleswig-Holstein was one of five pre-dreadnought, Deutschland-class battleships, not to be confused with a later class of pocket battleships of the same name. She was named for Schleswig-Holstein, Germany's most northern region. The ship was built at Germania Werft Shipyard in Kiel and commissioned into the Kaiserliche Marine on 6 July 1908.
Though obsolete by the outbreak of World War II she took part in some operations. At the end of August 1939, Schleswig-Holstein sailed to Danzig now known as Gdańsk, under the pretext of a courtesy visit, and anchored in the channel near Westerplatte. On 1 September 1939, at 4.45 a.m. she began to fire 280mm and 170mm shells at the Polish garrison there. The Battle of Westerplatte lasted seven days.
After the capitulation of Westerplatte, the Schleswig-Holstein battered Gdynia, Kepa Oksywska, and the Hel Peninsula. During the bombardment of the last she was hit by a 152 mm shell from the Polish battery.
The ship was used as a training vessel for the majority of WWII, and was sunk by British bombers in Gotenhafen in December 1944.
SMS Schleswig-Holstein - Poland Travel Guide