Dardanelles Strait between the Aegean and the Sea of Marmara, separating European and Asian Turkey.

Defence of the Realm Act(s) (DORA) Emergency legislation, first drafted by the Committee of Imperial Defence (CID), giving the British government extra coercive powers during wartime. The first Act was passed into law on 8 August 1914 and was extended a further six times during the First World War.

Denikin, General Anton (1872-1947) Leading general in the 'White' forces that opposed the Bolsheviks during the Russian civil war (1917-21). Commanded the anti-Soviet forces in the whole of southern Russia from January 1919. His brutal rule in the north Caucasus and the Ukraine, however, made him a difficult partner for the Allies. Defeated in March 1920, he fled abroad and remained in exile for the rest of his life.

Derby, Lord (1865-1948) Conservative war secretary, 1916-18; ambassador to France, 1918-20. Responsible for the unpopular 1917 demobilisation scheme that ordered men who had worked in key branches of British industry to be returned home first.

Dimitrijevic, Dragutin (1876-1917) Head of Serbian military intelligence, nicknamed Apis ('The Bull'). Advocated the use of violence to attain a greater Serbia and also headed the Serbian terrorist group, the Black Hand, one of whose protégés - Gavrilo Princip - assassinated Archduke Franz Ferdinand in Sarajevo on 28 June 1914. Dimitrijevic was executed for plotting against the Serbian royal family in July 1917.

Discovery Purpose-built ship that served as the main vessel for Captain Scott's National Antarctic Expedition (1901-04).

Dogger Bank Extensive submerged sandbank in the North Sea between northern England and Denmark. Site of British naval victory over Germany on 24 January 1915.

Dominions Name given to the self-governing divisions of the British empire: Australia, Canada, New Zealand and South Africa.

Dujaila Town two miles south of Kut-al-Amara on the River Tigris in Mesopotamia, where the British relief force under General Fenton Aylmer was defeated on 7 March 1916.

Dyer, Brigadier-General Reginald (1864-1927) British army general who gave the order to fire that prompted the Amritsar massacre on 11 April 1919, in which 379 people died.