SMS Nassau was the first dreadnought battleship built for the Imperial German Navy, a response to the launching of the British battleship HMS Dreadnought. Nassau was laid down on 22 July 1907 at the Kaiserliche Werft in Wilhelmshaven, and launched less than a year later on 7 March 1908, approximately 25 months after Dreadnought was launched. She was the lead ship of her class of four battleships, which included Posen, Rheinland, and Westfalen.