The British Gallipoli Campaign (1915–16) was aimed at seizing the Dardanelles and Constantinople but was defeated by the Ottomans, and the Allies did not gain control of the region until occupying it in November 1918, after the end of the war. By that time, the Communist Bolsheviks had seized power in Russia during the October Revolution of 1917 and had signed a separate peace with the Central Powers in March 1918, dropping out of the war. As the Allies therefore no longer considered Russia among their number, and, indeed, did not even recognize the legitimacy of the Bolshevik government, the agreement was never implemented.