After Estonia was incorporated in the Soviet Union, it was given a new anthem. It is interesting to note that while the lyrics of many state anthems of the Soviet Republics contain assurances of friendship and cooperation between Russians and the people of the respective Soviet Republic, this is missing from the Estonian State anthem (but mention of the Soviet Union is present).
The version presented here, adopted in 1956, is a slight change from the original lyrics in that the third verse had references to Stalin, which became obsolete after his death. (There was also a minor change to a line in the first verse.) During the Soviet occupation of Estonia, the Estonian anthem was banned, however a poem set to music by Gustav Ernesaks (the composer of the Estonian SSR’s anthem) became a popular “unofficial national anthem” until independence and the former anthem was restored in 1990.
Special thanks to: Yrjo Makela for some of this information.