Bruce Dickinson has admitted Iron Maiden "weren't necessarily friends" when he started out with the band.
The 59-year-old singer joined the group in 1981 following the release of their first two albums and he believes the heavy metal outfit - made up of Steve Harris, Dave Murray, Adrian Smith, Nicko McBrain and Janick Gers - have been going for so long because they have grown to get on over the years.
He said: "We were all born out of the same mother, Iron Maiden, and so over the years, we've learned to get on with each other. We've survived because we weren't necessarily friends at the beginning in the ways that some bands are but we have become friends over the years."
While Bruce and Steve have previously clashed, the frontman admits they have both "got better" at working alongside one another after a difficult initial period.
He said: "We get on very well actually. I think we do anyway. He probably thinks I'm a ****. We see the drama in what we do in each other. He has got better at working with me. I've got better at working with him.
"When we first got together, we were almost headbutting each other on stage. You go through phases like that and it makes you stronger."
Bruce wasn't involved in the 1980 self-titled debut record and second album 'Killers', and he thought the 'Fear of the Dark' hitmakers' first record sounded "s**t" and more of a punk LP than heavy metal.
Speaking to The Irish Times, he added: "Ironically, people thought Iron Maiden was a bit of a punk band because it [the debut album] sounds s**t.
"When Killers came out, people thought Iron Maiden had come across all smooth and refined. We were never supposed to be a punk band. Steve hated punk. I didn't hate punk, but, at the same time, it never did a great deal for me.
"I always thought it was strictly limited by their alleged lack of music ambition."