Dave Mustaine was one of the main creative forces driving Metallica during the band's early years, but by the spring of 1983, his increasingly alienated bandmates knew he needed to go.

Anthrax guitarist Scott Ian was a close observer of the band dynamic during this period, a time he recalled in his memoir I’m the Man: The Story of That Guy From Anthrax. As Ian points out, Mustaine's drinking was the driving factor behind his dismissal, but he was hardly alone in abusing alcohol; the difference in his case was that when he drank, he tended to get mean.

"They were all drinking buddies and they did stupid s---. But Dave was a little stupider," wrote Ian. "And when he was really drunk, he could be a total a---hole. Late at night he would dump piles of trash in front of other bands’ rehearsal room doors, so when they’d show up the next day their whole front door would be covered with a mountain of garbage. And they’d know which band did it because Metallica were the only ones sleeping there. So all these musicians would knock on Metallica’s door, wanting to beat them up."

In Mustaine's own book, Mustaine: A Heavy Metal Memoir, he attributes the final break to a physical altercation that took place between himself and guitarist James Hetfield after Hetfield got between Mustaine and original Metallica bassist Ron McGovney — and ended when, according to Mustaine, "I threw a right cross that landed flush against James' face, turning his mouth into a pile of bloody Chiclets."

Whatever happened between Mustaine and the rest of the band in the days before his dismissal, they called Exodus guitarist Kirk Hammett on April 1, 1983, to invite him for an audition.

Mustaine remained unaware of Hammett's invitation — and part of the lineup — until after the band's April 9, 1983, gig. Ian remembers witnessing a soundcheck by billmates Vandenberg that was marred by a drunken tantrum by the guitarist, who was "screaming at them that they sucked and they should get the f--- off the stage," but he says he was still surprised when he showed up at the rehearsal facility "a day or two later" and discovered Mustaine was out of the band.

Saying that the April 9 gig was "the last straw," Ian describes a plan implemented "with the precision of a military air strike," which culminated with other members of Metallica buying a one-way bus ticket to Los Angeles and waiting until Mustaine passed out drunk. "They woke him up while he was still mostly incoherent and fired him. He had passed out in his clothes, so they didn’t have to help him get dressed," he wrote. "They just collected his stuff, which they had mostly packed in a bag already, and literally put him on the bus before he understood what was happening. Then they made plans to send him his gear."

The unceremonious firing only increased the chip on Mustaine's shoulder — he's said he "wanted blood" after he was let go — and he held onto his resentment long after founding Megadeth and finding multi-platinum success on his own, as evidenced by his tearful summit with drummer Lars Ulrich during the Metallica documentary Some Kind of Monster. But eventually, the two sides managed to find some level of rapprochement, and Mustaine has even joined his former bandmates onstage.

The parting of the ways between Metallica and Mustaine was definitely a turning point for both of them, but even if bitterness lingered for Mustaine, all parties involved have done pretty well for themselves in the long run. "It was necessary," said Hetfield in a 2009 interview, quickly adding, "It's obvious that he had the same drive as us — he went on to do great things in Megadeth. ... He's an amazing, talented person."

Metallica Albums Ranked