After four No. 1 studio albums, millions of records sold, an armload of hit singles, a hit live LP and video, and a Grammy, Sammy Hagar's tenure with Van Halen came to an end with a single phone call on June 16, 1996.

As both sides later admitted, Hagar and Eddie Van Halen had been at loggerheads for some time. According to Hagar, the duo's once harmonious songwriting relationship hit a sour patch during the sessions for their 1995 Balance album and never quite recovered.

"That was the record where if I said black, Eddie said white, and I'd say, 'Okay, white,' he'd say, 'No, I want black,'" he told Rolling Stone. "I'd say, 'Okay, well, I wanted black to begin with.' Then Eddie would go, 'Well, I don't know what I want, I'll let you know when I do.' He just wanted the opposite of what I wanted."

That adversarial tone held through the tour in support of the album, compounded by the death of longtime manager Ed Leffler and changes brought by his replacement, Ray Danniels, with whom Hagar rarely saw eye to eye. This conflict would prove particularly fateful during the months after Van Halen returned from the road after the Balance tour — a period in which Hagar wanted to take time off, but Eddie and Alex Van Halen were eager to get back to work.

"Eddie and Al went right into the studio," Hagar claimed in 1997. "They said they had to make money, but I said, ‘Whoa, are you crazy? We’re not hurting for money.’ I wanted to spend two months with my new baby, then make another record. … But Eddie said, ‘I’m frustrated because you never do what I ask you to do.’"

Eddie's displeasure also reportedly stemmed from Hagar's decision to record new music for a contract-fulfilling solo best-of set, which turned into a bigger sticking point when Hagar objected to the notion of a Van Halen hits collection — with its own new songs — and recording material for the Twister soundtrack. It all came to a head on Father's Day of 1996.

"I said, 'Sam, if you want to make another record or do another tour, you've got to be a team player. Van Halen is a band — not the Sammy Hagar show, not the Eddie Van Halen, Alex Van Halen or Michael Anthony show," Eddie told Guitar World later that year. ""He finally said, 'Yeah, goddammit, I'm fuckin' frustrated. I want to go back to being a solo artist.' I said, 'Thank you for being honest.' We ended hanging up like everything was cool because it was all out in the open. He'd admitted that he wanted to do solo stuff. And I said, 'Well, you can't be in a band and do that, too, so see ya.' I didn't fire him. He just quit."

Hagar disputed Van Halen's version of events. But whether he quit or was fired, the end result was the same: One of the most successful rock combos of the '80s and '90s was without its frontman. In the short term, and to complete the two new songs pegged for the greatest hits record Hagar had fought against, former singer David Lee Roth was brought briefly back into the fold — something Hagar found unforgivable.

"After I left, he drove to David Lee Roth's house, and man, that's worse than sleeping with the enemy," he told the Los Angeles Times. "We bumped heads, and the next thing I know, Eddie calls and David Lee Roth is back."

Roth's brief return opened a tumultuous era for Van Halen. After showing their original singer the door again, they hired ex-Extreme frontman Gary Cherone, who took the mic for 1998's Van Halen III before being let go. In 2004, the band reunited with Hagar — recording, ironically enough, a few new cuts for another best-of compilation before heading out on the road for an ultimately ill-fated tour. Roth returned again in 2007, sticking around for a series of tours and 2012's A Different Kind of Truth LP.

Hagar, meanwhile, jumped right back into his solo career, releasing Marching to Mars in 1997 and continuing to put out records on a regular basis — on his own, with his band the Waboritas and later with Chickenfoot. Questions of a reunion have continued to dog both sides — and those hopes were raised when Sammy and Eddie traded tweets in early 2016 — but as Hagar later insisted, his reaching out was prompted by the realization that neither of them was getting any younger.

"It just makes you stop and think that, you know, with my relationship with Eddie Van Halen and stuff that’s always been in the toilet, it makes you say, ‘I don’t want to be buried with any regrets or bad vibes like that,'" he pointed out. "It makes you want to be just friends with everybody and say, ‘Hey look, forget it.'"

The Best Song From Every Van Halen Album

They released a dozen albums over their career. These are the songs for your playlist.

See Rock’s Epic Fails: Van Halen Edition

More From 97X