Way back in the mists of time, in the days when rock giants walked the earth, the name Ozzy Osbourne was synonymous with subversive and dark. Back then, Ozzy was the singer in Black Sabbath, and they meant business. In an era when it seemed possible to measure a bands musical prowess by how heavy they were, they didnt come any weightier than Black Sabbath.

There were, its probably fair to say, none-more-black. A four-piece formed from the ashes of two locally well-known groups called The Rare Breed (Ozzy and bassist Geezer Butler) and Mythology (guitarist Tony Iommi and drummer Bill Ward), all four founding members of the original Black Sabbath grew up within half-a-mile of each other, in the same narrow, grey streets of Aston, a tiny Birmingham suburb then struggling to come to terms with the mess Hitlers bombs had made of it. Though they all shared a deep love of music - The Beatles for Ozzy, the Mothers Of Invention for Geezer, the Shadows and Chet Atkins for Iommi, and Gene Kruppa for Ward - they all saw the opportunity to form a successful group, Ozzy would tell me, as the quickest way out of the slums.

This biography tells the story of how they made that dream come true - and how it then turned into a nightmare for all of them. How at the height of their fame, Sabbath discovered they had been so badly ripped off by their managers they did not even own their own songs. How they looked for salvation from Don Arden - an even more notorious gangster figure, who resurrected their career but still left them indebted to him, financially and personally. And how it finally came to a head when in 1979 they sacked Ozzy: For being too out of control - even for us, as Bill Ward put it. Of course the story does not end there.

The next 15 years would see a war break out between the two camps: the post-Ozzy Sabbath and Ozzy himself, whose solo career overshadowed Sabbath to the point where, when he offered them the chance to reform around him again, it was entirely on his terms. Or rather, that of his wife and manager - and, to add a further bitter twist to the tale for Sabbath, daughter of Don Arden - Sharon Osbourne.