HMS Princess was launched in 1905 as Kronprincess Cecilie. She was detained 1 November 1914 and seized. She was renamed Princess in 1915 and converted to an Armed Merchant Cruiser on 9 January 1916. In this configuration, she was used as a dummy for the battleship HMS Ajax. All dummies were converted at Belfast by Harland and Wolff. All superstructure and guns were made of wood. The Princess/Ajax patrolled around Loch Ewe.