The Sacred War, English subtitles - Victory Day Song 1945

The music is by Alexander Alexandrov.

The circumstances of the composition and first performance of the song were hurried; the lyrics were published on 24 June 1941.  Alexandrov immediately wrote the music for them, writing the notes out on a blackboard for the singers to copy manually. The first performance was on 26 June at Belorussky Railway Station, where according to eyewitnesses it was sung five times in succession.

Here's some historical info about this song.

It was composed a few days after the war started.
http://musicofheroes.com/section/wake-up