The early '90s has gone down in the history books as the period when grunge took over the industry in virtually every manner. But there were still two bands that had come to prominence in the ‘80s that were unaffected by the rise of Nirvana, Pearl Jam and all those other artists.

Sitting pretty at the dawn of the '90s, Guns N’ Roses and Metallica decided to kick it up a notch, pairing for a stadium tour that was announced on May 12, 1992.

“There could not have been a bigger rock 'n' roll bill,” GNR guitarist Slash said in his eponymous 2007 memoir. “It was too cool. They had just released the Black Album and we were riding high with Use Your Illusion I and II.”

Hatched by Metallica drummer Lars Ulrich – who at the time was so taken by GNR he started wearing a white leather jacket in the style of Axl Rose circa the “Paradise City” video – the tour was set to take place that summer across North America.

According to the book Into the Black: The Inside Story of Metallica (1991-2014), a meeting between Ulrich, Rose, Slash, Metallica's James Hetfield and their respective management representatives took place in the fancy Los Angeles French restaurant Le Dome, ostensibly to iron out the logistics, of which there would be many.

Who goes on first? Who is going to support? How much is the purse each night? In order, the answers were: Metallica, Faith No More (after Nirvana declined) and a lot – about $750,000 per show.

“We had a meeting before it began because the Metallica camp was concerned," Slash recalled. "We were having major problems getting onstage on time, riding that high–low roller coaster. Metallica was not a band to pull that kind of shit at all, so they wisely opted to play first so as to avoid being pulled down by our bullshit.”

Watch an Interview with Lars Ulrich and Slash on MTV

Slash and Ulrich held a press conference at the Hollywood club Gaslight to reveal the details of the trek.

“I’ve always wanted to play with these guys, ever since we met them in 1987,” Ulrich said. “I’m the one who had all the late night conversations with the various members of Guns. Back in ’87, we were the bigger band, then they became the biggest band in the universe. Now, in the hard-rock scene of 1992, we’re the two biggest bands. Taking the two biggest bands from one genre of music and putting them together is unprecedented.”

Slash added: “There has been, like, major obstacles … but we still really want to do this. But we’ll get around it.”

Ulrich admitted that he didn't “think any of us realized when we sat down and had our drunken talks about doing this tour together, how tough it would be to get the three months of this happening – because if it was left to the managers, agents and accountants, this would have never got off the ground.”

Meanwhile, Slash said he hadn't “seen anything like this happen since I was a kid. It was bands going out, having these huge festivals, and everything changed while I was coming up as a guitar player, everything just sort of changed – it got really boring.”

“Boring” is the last word to describe the 26-date march. Kicking off at RFK Stadium in Washington, D.C., on July 17 and running through early October when it came to a close in Seattle, the tour was fraught with episodes like the Montreal date when Hetfield was burned in a pyrotechnics accident and when Rose ended his band's set prematurely, leading to a full-scale riot.

That was the low point of a three-month journey that often had GNR going on hours late and Rose stalking offstage mid-set. But for audiences who saw one of the shows, they witnessed a chaotic and fascinating experiment in music history.