The Estonian Soviet Socialist Republic (Estonian SSR or ESSR; ENSV; ЭССР, Estonskaya Sovetskaya Sotsialisticheskaya Respublika ESSR) was a republic of the Soviet Union, administered by and a subordinate of the Government of the Soviet Union. The ESSR was initially established on the territory of the Republic of Estonia on July 21, 1940, following the invasion of Soviet troops on June 17, 1940, and the installation of a puppet government backed by the Soviet Union, which declared Estonia a Soviet state. The Estonian SSR was subsequently incorporated into the USSR on August 9, 1940. This territory was also occupied by Nazi Germany from 1941 to 1944.