The Moldavian Soviet Socialist Republic (Moldavian SSR or MSSR; Moldovan/Romanian: Република Советикэ Сочиалистэ Молдовеняскэ or Republica Sovietică Socialistă Moldovenească; Moldavskaya Sovetskaya Sotsialisticheskaya Respublika) was one of the fifteen republics of the Soviet Union. After the Declaration of Sovereignty on June 23, 1990 and until 23 May 1991 it was officially known as the Soviet Socialist Republic of Moldova. From 23 May 1991 until the declaration of independence on 27 August 1991, it was renamed the Republic of Moldova whilst remaining a constituent republic of the USSR.