First Republic of Armenia

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 (28th de jure, 30th de facto) 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 Federation.

Source: Wikipedia — First Republic of Armenia (CC BY-SA 4.0)