One day I came in with this riff and Abaddon started pounding the toms to it in a really tribal way. I was expecting a straight beat, but this rolling thing started happening with the song. And the solo is just a bunch of single, sustained notes with feedback - just noise, really. I had some lyrics and Conrad helped me finish them off. Then we put this backward part in the beginning to make the song sound more evil. I played that on my Flying V copy and my Marshall. There was nothing fancy. We couldn’t afford it.James "Mantas" Dunn / Venom interview, Guitar World, 2017
Look Out! Beware! When the full moon's high and bright. In every way, I'm there. Every shadow in the night. 'Cause I'm evil, in league with Satan!
Listen to the original "In League with Satan", recorded before Welcome to Hell, below. While it's different from the album version, it's also different from the bonus track 7" version on some reissues of Welcome to Hell (easy to spot the correct single version - no backward intro).
...what we did was, we sent a tape to a magazine called Sounds, where Geoff Barton was the editor. Geoff loved the tracks and he put the three tracks in his playlist and then he did a review for the WHITE SPIRIT single and at the end of it he put this thing saying... 'And if Neat Records gets its shit together it should release a single by the band called VENOM!' So we approached them back them and said, 'Look it's time for a single!' So we went in... We actually recorded 'Live Like An Angel', 'Angel Dust' and 'In League With Satan', but the record company liked 'In League With Satan', so...Conrad "Cronos" Lant / Venom interview, Voices from the Darkside, 1995
We did [the single recording] separately, we did them first. We came in and just did those three songs, but left off 'Angel Dust' and then we got scheduled back in for a week to come in and do the album and three days later we were presenting the tapes!Conrad "Cronos" Lant / Venom interview, Voices from the Darkside, 1995
Edwin Pouncey's review from Sounds, 13th June 1981:
Venom are totally corrupt and while this piece of demon riddled canker pales in comparison to the version they laid down and sent to the king of Kerrang!, it still makes the best listening of this genre since 'Iron Man' by Black Sabbath As for the rest of you, wake up at the front!