Armenia was annexed by Bolshevist Russia and along with Georgia and Azerbaijan, it was incorporated into the Soviet Union as part of the Transcaucasian SFSR (TSFSR) on 4 March 1922. With this annexation, the Treaty of Alexandropol was superseded by the Turkish-Soviet Treaty of Kars. In the agreement, Turkey allowed the Soviet Union to assume control over Adjara with the port city of Batumi in return for sovereignty over the cities of Kars, Ardahan, and Iğdır, all of which were part of Russian Armenia.
When was the Transcaucasian SFSR formed?
4 March 1922