From the Wikipedia page [1]
The Mountainous Republic of the Northern Caucasus (MRNC; also known as the Mountain Republic or the Republic of the Mountaineers; Russian: Республика Союза Горцев Северного Кавказа; Respublika Soyuza Gortsev Severnogo Kavkaza) was a short-lived state situated in the Northern Caucasus that existed from 1917 until 1920. It broke away from the Russian Empire during the February Revolution, shortly before the start of the Russian Civil War.
MRNC included most of the territory of the former Terek Oblast and Dagestan Oblast of the Russian Empire, which now form the republics of Chechnya, Ingushetia, North Ossetia–Alania, Kabardino-Balkaria, Dagestan and part of Stavropol Krai of the Russian Federation. The total land area was about 125,000 square kilometers (48,000 sq mi), with a population of about 1 million. Its capital was initially at Vladikavkaz, then Nazran, and finally Temir-Khan-Shura.
The state was captured by Soviet Russian forces in 1920, who transformed it into the Mountain Autonomous Soviet Socialist Republic.