Before he assembled Dio, Ronnie James Dio was a well-known figure in the heavy metal world. With Elf, Rainbow, and Black Sabbath, Dio was a top hard rock singer with a solid commercial appeal; he was responsible for reviving Sabbath's sagging fortunes in the early '80s. After three years with Sabbath, he left to form his own band in 1983; it featured guitarist Vivian Campbell (who would later play with Whitesnake and Def Leppard), drummer Vinny Appice, ex-Rainbow bassist Jimmy Bain, and keyboardist Claude Schnell. For the rest of the '80s, Dio was one of the top metal bands, with a crunchier, more streamlined version of Sabbath's mystical vision.
In 1990, Dio disbanded the group and returned to Black Sabbath for a brief time in 1991 and 1992; he soon left the band again, assembling a revamped version of Dio and began touring again in support of LPs like 1994's Strange Highways and 1995's Angry Machines. Following 1998's two-disc Inferno: Last in Live, the group resurfaced in the spring of 2000 with Magica. Dio's medieval-themed metal returned two years later, when the Killing the Dragon album arrived in the spring of 2002. The album was a serious endevor, but Dio also learned to make fun of his image after years of defending it, inviting comedy duo Tenacious D to star in the video for "Push" and even including the clip on the fall re-release of Killing the Dragon. ~ Stephen Thomas Erlewine, All Music Guide