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 First Republic of Armenia, officially known at the time of its existence as the Republic of Armenia, was an independent Armenian state that existed from May 1918 to 2 December 1920 in the Armenian-populated territories of the former Russian Empire known as Eastern or Russian Armenia. The republic was established in May 1918, with its capital in the city of Yerevan, after the dissolution of the short-lived Transcaucasian Democratic Federative Republic. It was the first Armenian state since the Middle Ages.