SMS Ostfriesland was the second vessel of the Helgoland class of battleships of the German Imperial Navy. Named for the region of East Frisia, Ostfriesland‍ '​s keel was laid in October 1908 at the Kaiserliche Werft dockyard in Wilhelmshaven. She was launched on 30 September 1909 and was commissioned into the fleet on 1 August 1911. The ship was equipped with twelve 30.5-centimeter (12.0 in) guns in six twin turrets, and had a top speed of 21.2 knots (39.3 km/h; 24.4 mph).