Caucasus campaign

The Caucasus campaign comprised armed conflicts between the Russian Empire and the Ottoman Empire, later including Armenia, Azerbaijan, Georgia, the Mountainous Republic of the Northern Caucasus, the German Empire, the Central Caspian Dictatorship, and the British Empire, as part of the Middle Eastern theatre during World War I. The Caucasus campaign extended from the South Caucasus to the Armenian Highlands region, reaching as far as Trabzon, Bitlis, Mush and Van. The land warfare was accompanied by naval engagements in the Black Sea.

The Russian military campaign started on 1 November 1914 with the Russian invasion of Turkish Armenia.

In February 1917, the Russian advance was halted following the Russian Revolution. The Russian Caucasus Army soon disintegrated and was replaced by the forces of the newly established Transcaucasian state, comprising partly of Armenian volunteer units and irregular units which had previously been part of the Russian Army. During 1918 the region also saw the establishment of the Central Caspian Dictatorship, the Republic of Mountainous Armenia and an Allied intervention force, nicknamed Dunsterforce, composed of troops drawn from the Mesopotamian and Western Fronts.

On March 3, 1918, the campaign had terminated between the Ottoman Empire and Russia with the Treaty of Brest-Litovsk, and on June 4, 1918, the Ottomans signed the Treaty of Batum with Armenia, Azerbaijan, and Georgia gaining independence. However, conflict continued as the Ottoman Empire was still engaged with the Central Caspian Dictatorship, the Republic of Mountainous Armenia, and the Dunsterforce of the British Empire until the Armistice of Mudros was signed on October 30, 1918.

The Turkish genocide of the Armenians began in April 1915 when 250 Armenians were arrested. The official reason was that the Armenians were in league with the Russians and could serve as a potential fifth column. The genocide continued until 1918.