Along the way, the band transformed from cocky Irish upstarts into bona fide rock stars, eventually reaching number one with 1983's War.

As the band release re-mastered versions of those early recordings, complete with bonus tracks and new artwork, Lillywhite recalls the tension, tedium and inspirations behind the recording sessions.

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Steve Lillywhite talks through the recording of four early U2 tracks

BOY (1980)

It was originally going to be produced by Joy Division cohort Martin Hannett, but he dropped out after singer Ian Curtis committed suicide.

I always remember on that first album, I was sitting at the mixing desk with the band behind me and suddenly I heard all this giggling. I turned around and suddenly they all went sheepish, shushing each other like teacher was looking at them.

I think they would admit that, like all teenage boys, they hadn't lived long enough to acquire a personality… There wasn't much talking in the studio. It was quite serious.

We recorded in a place called Windmill Lane in Dublin. It was great for traditional Irish music but no Irish rock band had recorded there. Thin Lizzy came to London to make their records. The Boomtown Rats didn't record in Ireland either.

But that meant we couldn't record until the evening, because this girl was sat answering the phones all the day. Even then, we couldn't turn the ringer off the phone so occasionally it would go off mid-take.

It was all pretty slapdash. But funnily enough, it's not unlike how the band still records.

OCTOBER (1981)

Another setback came when a briefcase full of lyrics was stolen, forcing Bono to rewrite some of the songs.

U2 could have gone two ways after Boy. They could have broken out and gone bigger - but in fact what they did was they shrunk a little bit. They were a little bit scared of the world, I think.

Yes, there were Bibles dotted around the room during the recording. There was a fair amount of that. But I was so busy trying to pull teeth - trying to make an album - that it sort of washed over me.

It was completely chaotic and mad in the studio and, obviously, Bono's lyrics being lost contributed to the atmosphere. I'm not sure whether any of those words would have been used on the album - only he knows that - but certainly it would have been a starting point.

In the end, October wasn't a big record. After the rock and roll things they tickled on the first album, people were expecting something that was a bit more "rawk". What they got, in fact, was perhaps an indication of where the band would go later on in their career.

The Joshua Tree was probably where they married the sensibilities of those first two albums and that was where they struck gold.

WAR (1983)

Re-energised and re-focused, the band also gained a political edge with songs like Sunday Bloody Sunday.

The band had been questioning whether their beliefs could coincide with their new experiences. And in the end it was their manager Paul McGuinness who sat down and said, "don't be so silly, you can have them both".

In his sort of matter-of-fact way, he convinced them that the world would be better if they carried on making music.

But I think we all realised that there'd been a step back with October and that, if we were going to go for it, we had to have the urgency of the first album.

I remember Bono saying to The Edge, "don't be like The Edge. Be like Mick Jones from the Clash".

Because Edge is like a scientist. He has the white coat on and pencils in his pocket. And I think what Bono wanted him to do was take off the white coat and put on the star-studded leather jacket.

Edge was the only one who stayed at home. And he presented us with Sunday Bloody Sunday when we got back. And we just went, "wow, this is really good".

I listened to the album the other day and certainly New Year's Day is a spectacular piece of work. It's sonically great, it's mature, and Edge's piano-playing - he's got such a great touch. And that bassline was Adam's finest moment.

But it's funny, we didn't think of it as a single. It was one of the young interns in the studio who first said to me, "that song is brilliant". And we all went, "oh, really?"

One of the strange things about that album is that we used Kid Creole's backing singers, the Coconuts. They just happened to be in Dublin on tour, so we hung out with them and they came in and sang on Surrender. So it was sort of random - this serious Irish rock band having the Coconuts on their album.

But there's nothing U2 like better than a pretty woman.

The new versions of Boy, October and War are released on 21 July by Island Records. Steve Lillywhite was talking to BBC News entertainment reporter Mark Savage