Black Sabbath released its 18th studio album, Forbidden, in 1995, to negative reviews. The following months left the group at a crossroads. After a series of reunion tours from 1997 to 1999 – mostly with Ozzfest – the original line-up began work on a new album with producer Rick Rubin in the spring of 2001. These sessions were halted when Ozzy Osbourne was called away to finish tracks for his album Down to Earth, released in October that year. Tony Iommi recalled: "It just came to an end… It's a shame because [the songs] were really good." "It's quite different recording now…" he added. "In [the early] days there was no mobile phone ringing every five seconds. When we first started, we had nothing. We all worked for the same thing. Now everybody has done so many other things. It's great fun and we all have a good chat, but it's just different, trying to put an album together."
"We got very scratchy stuff," Ozzy explained in late 2001. "It never really materialised into much. It may be great, but I haven't heard it since, apart from the one song we were doing live ['Scary Dreams', played on Ozzfest 2001]. We produced our own stuff and then we handed the tapes over to Rick Rubin and that was the last I heard of it. I must confess… it wasn't the same way, anyhow. Geezer wasn't writing the lyrics anymore, I was having real big problems coming up with melody lines and topics to sing about… Tony was still firing off these amazing heavy metal riffs. He just goes, 'Here you go,' and comes out with one better than you've ever heard in your life. You'd think he'd run out of things to play. But, for all that, the chemistry just wasn't there."
After one more reunion tour in mid-2001, where they again headlined Ozzfest, Sabbath went back on hiatus. In March 2002, Osbourne's Emmy-winning reality TV show The Osbournes debuted on MTV, and quickly became a worldwide hit. It introduced Osbourne to a broader audience; and, to capitalise, Sanctuary Records (who own Sabbath's back catalogue) released the live album Past Lives, featuring material recorded in the 1970s, including the Live at Last album. The band remained on hiatus until mid-2004, when they returned to headline Ozzfest 2004 and 2005. In November 2005, Black Sabbath were inducted into the UK Music Hall of Fame, and in March 2006, after eleven years of eligibility, the band were inducted into the US Rock and Roll Hall of Fame.
While Osbourne was working on his new solo album in 2006, Rhino Records released Black Sabbath: The Dio Years, a compilation culled from the four Sabbath releases featuring Ronnie James Dio. For the release, Iommi, Geezer Butler, Dio and Vinny Appice reunited to write and record three new songs as Black Sabbath. The Dio Years was released on 3 April 2007, reaching No.54 on the Billboard 200, while the single "The Devil Cried" reached No. 37 on the Mainstream Rock Tracks chart. Pleased with the results, Iommi and Dio decided to reunite the Heaven and Hell era line-up for a world tour. Because the line-up of Osbourne, Butler, Iommi and Bill Ward were still officially called Black Sabbath, the new line-up dubbed themselves Heaven & Hell, after the album of the same name. Ward was to participate, but dropped out before the tour began due to musical differences with "a couple of the band members" as well as a "contractual dispute". He was replaced by former drummer Vinny Appice, reuniting the line-up that had featured on Mob Rules and Dehumanizer. After their only studio album The Devil You Know in 2009, Dio died after a battle against stomach cancer on 16 May 2010. Following a tribute concert with former Sabbath vocalist Glenn Hughes, Heaven & Hell disbanded.
On 11 November 2011, Sabbath hosted a private announcement ceremony at the Whisky a Go Go in Hollywood, California. Hosted by former Black Flag vocalist Henry Rollins, the event featured all four original Sabbath band members. At the event, Sabbath announced they would be officially reuniting, following months of rumours. The reunion was said to feature an appearance at the 2012 Download Festival, and a newly recorded studio album by Rubin expected to be released in late 2012. When Rollins asked the band why they chose to reunite, Iommi responded, "It's now or never. We get along great. Everything's really good." Butler commented that the new material was the "old Sabbath style and sound." Osbourne said he was "blown away", and, "I don't understand why it's happening. I mean, 45 years down the road and we've got a really great album to put out." On 18 November 2011, Black Sabbath announced that they would be touring Europe in May and June 2012.