Good things never last and Sabbath's first reconciliation with Dio was one of them.

But Iommi, Butler and Mob Rules-era drummer Vinny Appice's 1990 reunion with the mighty D eventually spawned a gem of an album with 1992's Dehumanizer. A significant return to form for Iommi after a shaky late eighties, it's markedly aggressive, and one of Sabbath's heaviest - just take a listen to After All (The Dead).

While Sabbath's commercial and critical stock rose with Dehumanizer, Iommi put the cat amongst the pigeons when he suggested the band capitalise on demand by supporting Ozzy Osbourne for two shows in Costa Mesa, California at the end of his 1992 tour.

This was a slight too far for Dio, who promptly quit. The band played on with none other than Rob Halford of Judas Priest filling in for a Birmingham metal all-star event.