 However, after the fall of the republic in December 1920, the 2nd Pan-Zangezurian congress held in Tatev on 26 April 1921, announced the independence of the self-governing regions of Daralakyaz (Vayots Dzor), Zangezur (including Dastakert), and parts of Mountainous Artsakh, under the name of the Republic of Mountainous Armenia ("Lernahaystani Hanrapetutyun").However, the self-proclaimed republic had a short life as the Red Army started conducting massive military operations in the region during June–July 1921, attacking Syunik from the north and east.As a result of fierce battles, the Republic of Mountainous Armenia capitulated on 13 July 1921, following Soviet Russia's promises to keep the mountainous region of Syunik part of Soviet Armenia.