State Defense Committee

The State Defense Committee () was an extraordinary organ of state power in the USSR during the German-Soviet War (Great Patriotic War) which held complete state power in the country.
General scope.
The Soviets set up the GKO on 30 June 1941 (a week after Nazi Germany invaded the Soviet Union on 22 June 1941) by a compound decision of the Presidium of the Supreme Soviet of the USSR, the Council of People's Commissars ("Sovnarkom"), and the Central Committee of the Communist Party of the Soviet Union. The war situation at the front lines required a more centralized form of government. The Supreme Soviet, however, continued unsuspended. On 18 June 1942 over a thousand members attended the 9th session of the Supreme Soviet in Moscow.)
Geoffrey Roberts sees the GKO as "a sort of war cabinet".
Composition.
The initial composition of the committee was such:
On February 3, 1942 the members of the committee also became the chairman of Gosplan Voznesensky and Mikoyan, while on February 20, 1942 was also included Lazar Kaganovich (Narkom of Transportation). By the end of the war on November 22, 1944 Nikolai Bulganin (Chairman of State Bank Directory) replaced Klim Voroshilov in the committee.
Further reading.
Glantz, David M. "When Titans Clashed: How the Red Army stopped Hitler". Lawrence, KS: University Press of Kansas, 1995. Overview of Eastern Front from Soviet side. 
Roberts, Geoffrey. "Stalin's Wars: From World War to Cold War, 1939-1953". New Haven, CT: Yale University Press, 2006. Post-revisionist study of Stalin's wartime and post-war leadership.