When Metallica, Slayer, Megadeth and Anthrax joined forces for select concerts billed as the "Big 4," it was a concrete move that signaled that the longstanding feud between Megadeth frontman Dave Mustaine and his former Metallica bandmates was indeed over. But how did this whole endeavor come to be?

Metallica frontman James Hetfield revealed how he got the ball rolling while guesting on Marc Maron's WTF podcast (audio below). "It really started [when Metallica was inducted into] the Rock and Roll Hall Of Fame [in 2009]," he began. "Getting nostalgic and thinking, 'My God, look at all the people that have helped us along the way and look who are still around. Let's say 'thank you' to them,'" states Hetfield, adding, "And so the 'Big Four' was kind of that thing."

"We're all still playing after thirty… whatever it was… thirty-two years," the Metallica frontman continued. "Let's go do a gig together. I mean, why shouldn't we? Let's celebrate the fact that we're still alive and playing music that we love."

As fans and critics look upon metal's history, the New Wave of British Heavy Metal is often cited as a turning point for the genre. "That's all I ever hear about. NWOBHM. Blah blah blah," Hetfield remarked. "What about the 'Big 4'? No one knows the 'Big 4.' Come on, let's make it known. Let's make some history here, and let people know, and put a mark there that, hey, the 'Big 4' was, and is, a force to be reckoned with."

The bad blood between Dave Mustaine and the Metallica camp had been highly publicized since Mustaine was ousted from the group in 1983, but both sides put history in the past. When asked about his relationship with Mustaine, Hetfield stated, "There's no reason [for things] to not be good [between us]. At this point, we've all freakin' fell off the wagon, we've all gone into the ditch, we've all gotten back on track, we've all learned from our stuff. And at the end of the day, it's just journeys — everyone is doing a different journey — and why would you hold a grudge with someone or vice versa?"

On Thanksgiving last year, Mustaine tweeted that he was thankful for his "Big 4 Brothers," adding he'd like to do more Big 4 shows. When Loudwire Nights host Toni Gonzalez spoke with Metallica bassist Robert Trujillo, she mentioned the tweet and Trujillo reflected on how much fun the shows were, stating in part, "It makes me feel good that Dave wants to take that journey again."

Listen to James Hetfield on the WTF Podcast

See Metallica and Megadeth in the Top 50 Metal Bands of All Time

See Metallica With Dave Mustaine in 10 Unforgettable Onstage Reunions

More From Eagle 102.3