"Invasion" is a song by the heavy metal band Iron Maiden and was released on The Soundhouse Tapes EP in 1979. It was rerecorded in 1981, and the rerecorded version was the B-Side to the Woman In Uniform single. The subject of the song is probably the basis for later released "Invaders", from the 1982 album The Number Of The Beast.
The Vikings are coming
You'd better get ready for we're having a fight