"Preussen"s peacetime career centered on squadron and fleet exercises and training cruises to foreign ports. The ship served as the flagship of II Battle Squadron of the High Seas Fleet for the majority of her career. During World War I, she served as a guard ship in the German Bight and later in the Danish straits. She participated in a fleet sortie in December 1914 in support of the Raid on Scarborough, Hartlepool and Whitby during which the German fleet briefly clashed with a detachment of the British Grand Fleet. "Preussen" had been temporarily assigned to guard ship duties in the Baltic in May 1916, and so missed the Battle of Jutland. Due to her age, she did not rejoin the fleet, and instead continued to serve as a guard ship until 1917, when she became a tender for U-boats based in Wilhelmshaven.