SMS Helgoland, the lead ship of her class, was a dreadnought battleship of the German Imperial Navy. Helgoland's design represented an incremental improvement over the preceding Nassau class, including an increase in the bore diameter of the main guns, from 28 cm (11 in) to 30.5 cm (12 in). Her keel was laid down on 11 November 1908 at the Howaldtswerke shipyards in Kiel. Helgoland was launched on 25 September 1909 and was commissioned on 23 August 1911.