The 2nd Pan-Zangezurian congress, held in Tatev, announced on 26 April 1921 the independence of the self-governing regions of Daralakyaz (Vayots Dzor), Zangezur, and Mountainous Artsakh, under the name of the Republic of Mountainous Armenia (Lernahaystani Hanrapetutyun).
Between April and July 1921, the Red Army conducted massive military operations in the region, attacking Syunik from north and the east.