ESSR meaning in Governmental ?

The Estonian Soviet Socialist Republic (Estonian SSR or ESSR; Estonian: Eesti Nõukogude Sotsialistlik Vabariik ENSV; Russian: Эстонская Советская Социалистическая Республика ЭССР, Estonskaja Sovětskaja Socialističeskaja Respublika ESSR) was a republic of the Soviet Union. The ESSR was initially established on the territory of the Republic of Estonia on 21 July 1940, following the occupation of Soviet troops on 17 June 1940 and the installation of a communist government backed by the Soviet Union, which declared Estonia a Soviet constituency. Estonia was subsequently incorporated into the Soviet Union as a Soviet Republic on 6 August 1940. The territory was occupied by Nazi Germany in 1941 and administered as a part of Reichskommissariat Ostland until it was reconquered by the Soviet Union in 1944 during World War II.

Most countries did not recognize the incorporation of Estonia de jure and only recognized its Soviet government de facto or not at all. A number of countries continued to recognize Estonian diplomats and consuls who still functioned in the name of their former government. This policy of non-recognition gave rise to the principle of legal continuity, which held that de jure, Estonia remained an independent state under occupation throughout the period 1940–91.

On 16 November 1988, the Estonian SSR became the first republic within the Soviet sphere of influence to declare state sovereignty from Moscow. On 30 March 1990, the Estonian SSR declared that Estonia had been occupied since 1940 and declared a transitional period for the country's full independence. The Estonian Soviet Socialist Republic was renamed as the Republic of Estonia on 8 May 1990. The independence of the Republic of Estonia was re-established on 20 August during the 1991 Soviet coup d'état attempt the following year and the Soviet Union itself recognized the independence of Estonia on 6 September 1991.