Tannenberg Village on the Masurian Lakes in eastern Prussia. Scene of the first major clash of arms between Germany and Russia during the First World War. The Battle of Tannenberg (27-30 August 1914) ended in an overwhelming victory for the Germans, who killed, wounded or captured more than 150,000 Russian soldiers. It also avenged the legendary defeat of the German Teutonic Knights at the hands of Slav forces more than five centuries earlier in 1410.

Tannenberg memorial German memorial commemorating the dead from the Battle of Tannenberg in August 1914. Unveiled in 1927, it contains the tombs of 20 unknown soldiers who died on the Eastern Front during the First World War.

Tarnow Town in western Galicia. Austro-German forces under Mackensen launched a successful offensive against the Russian army between Tarnow and the nearby town of Gorlice on 2 May 1915.

Taylor, A J P (1906-90) British historian. Author of The Struggle for the Mastery of Europe, 1848-1918 (1954), which blamed the outbreak of the First World War on Germany's aggressive aspirations for continental supremacy.

'Temporary gentlemen' Term used to describe men who were temporarily promoted to officer class during the First World War.

Territorial Force(TF) Created in 1907 as the main standing reserve formation for the British armed forces. It subsequently became the Territorial Army (TA).

Territorial Force Nursing Service (TFNS) Formed in 1908 to provide medical support to the Territorial Force.

Tigris, River River in SW Asia, rising in southern Turkey and flowing south-east through Baghdad to meet the River Euphrates in SE Iraq, from where the two rivers flow on into the Persian Gulf.

Togoland (Togo) German colony in NW Africa. Scene of one of the earliest skirmishes of the First World War, when Allied troops forced the surrender of a small German force at Kamina on 26 August 1914. The territory was then divided into British and French spheres of control for the rest of the war.

Townshend, General Charles (1861-1924) Indian army officer who led the early successes of Anglo-Indian forces in Mesopotamia (1914-15). After defeat at the Battle of Ctesiphon (22-26 November 1915), however, he was forced to retreat with his men to Kut-al-Amara. After the surrender of British forces there in April 1916, he spent the rest of the war in comfortable captivity near Constantinople, before helping to broker armistice negotiations between Turkey and Britain at Mudros in late October 1918.

Toynbee, Arnold (1889-1975) British historian. Author of the 1915 book Armenian Atrocities: The murder of a nation.

Trade blockade Naval strategy adopted by Britain and its allies on the outbreak of war in August 1914, by which a concerted attempt was made to strangle all overseas supplies of foodstuffs and raw material to Germany and its allies. Known in Germany as the 'hunger blockade'.

Transcaucasia Territory straddling the Caucasus mountains that separated Ottoman Turkey from the Russian empire. Representatives of the main population groups in the region - Armenians, Azerbaijanis and Georgians - formed the Federal Republic of Transcaucasia in September 1917. It was, however, abolished in May 1918, as the independence movements were crushed by Bolshevik and Turkish forces.

Trans-Siberian railway Railway stretching across the eastern Russian province of Siberia. Guarded from May 1918 by Allied forces determined to protect their war supplies from Bolshevik incursions.

Trebizond Town on the Black Sea in the Ottoman province of Armenia, now known as Trabzon. Almost 17,000 of its Armenian inhabitants were massacred by Turkish troops in July 1915.

'Trench foot' Form of frostbite affecting the feet of people standing for long periods in cold water. A common affliction in the trenches on the Western Front during the First World War.

Trianon, Treaty of Allied peace treaty with Hungary, signed on 4 June 1920. The delay in concluding terms was due to the Communist seizure of power in the country in March 1919 and the subsequent dictatorship of Béla Kun.

Triple Alliance Alliance of Austria-Hungary, Germany and Italy in early 20th-century Europe.

Triple Entente Informal alliance of Britain, France and Russia in early 20th-century Europe.

Trotsky, Leon (1879-1940) Leading Bolshevik politician. Led the Soviet negotiations for a separate peace with Germany that were concluded at Brest-Litovsk in March 1918 and, from 1919 onwards, successfully organised the Red Army in its struggle against the counter-revolutionary 'Whites'.

Tsingtau (Tsintao, Qingdao) German port and fortress on the eastern coast of China. Surrendered to Anglo-Japanese forces on 7 November 1914 after a week-long bombardment.