Sovnarkom (Russian language СовНарКом, the abbreviation of the phrase "Совет Народных Комиссаров", Sovet Narodnykh Komissarov", the Council of People's Commissars, sometimes Russian СНК, the SNK), was the name of administrative arm of the Soviet governments until 1946.
The Council of People's Commissars with chairman Vladimir Lenin was formed at the 2nd All-Russian Congress of Soviets on November 8, 1917.
The 1918 Soviet Constitution made the Sovnarkom of the R.S.F.S.R responsible to the Congress of Soviets for the "general administration of the affairs of the state." The constitution enabled the Sovnarkom to issue decrees carrying the full force of law when the congress was not in session. The congress then routinely approved these decrees at its next session. (In fact, the Sovnarkom had already exercised governmental authority of the RSFSR since November 1917 after the Second All-Russian Congress of Soviets).
After the formation of the USSR, the SNK of the USSR was created under proposals of its Constitution; see Premier of the Soviet Union for the chronology of its chairmen. The Soviet republics retained their own governments which dealt with domestic matters; they were also named Sovnarkom by conventions of their pre-Union legislation.
In 1946 all of the Sovnarkoms were renamed into the Council of Ministers ('Совет Министров - Sovet Ministrov, or Совмин - Sovmin) together with renaming of People's Commissariats (sl.: НарКомат (NarKomat) into ministries and People's Commissars (sl.: НарКом, NarKom) into ministers.