Source: Fleets of the world 1915. Compiled from official sources and classified according to types.
Orion-class
Notes
1. Building ordered under 1909 Naval Estimates. Laid down by William Beardmore and Company, Dalmuir, Scotland on 5 April 1910, launched on 1 May 1911, commissioned on1 December 1912, laid up after 1918, decommissioned in 1921 and sold to be broken up in 1922 under the Washington Naval Treaty terms. Building costs 1.891.164 pond sterling. Building costs 1.892.823 pond sterling and she caused the bankruptcy of the shipyard which built her. Of the Orion-class consisting of the Orion, Monarch, Conqueror and Thunderer preceded by the Colossus-class and succeeded by the King George V-class.
2. Result of the Washington Naval Conference between November 1921-February 1922 signed by USA, England, Japan, Italy and France to limit the building of battleships, battle cruisers and aircraft carriers and to limit the possession of such capital ships by stopping completion of breaking up already existing.
3. Building was ordered by the Ottoman government and to be named Reşadiye. Modified design based on the British King George V-class using features of HMS Iron Duke. When the First World War broke out seized by the British government as ordered by Winston Churchill at that moment First Lord of the Admiralty. Laid down on the Vickers shipyard, United Kingdom on 6 December 1911, launched on 3 September 1913, completed in August 1914m taken over by the British Royal Navy on 22 August 1914 (she was already completed pair for by the Ottoman government!), since October 1919 part of the naval reserve, drill ship at the Chatham Dockyard since December 1919, refitted at the Devonport Dockyard between July-August 1920, regarded the Washington Treaty she was to become a training ship, decided to dispose her in May 1922, sold to the ship breaking firm Cox and Danks on 19 December 1922 and broken up at Queensborough, United Kingdom in 1923.