Iommi owns the name outright and is entitled to do anything he likes with it. But Osbourne says he's been arguing the point for three years, and believes all four founding members of the band - himself, Iommi, Geezer Butler and Bill Ward - should co-own the brand.

He says he's been forced to go to court after failing to persuade Iommi to "do the right thing" by any other means - and he's only taking action "with regret". In a statement Osbourne explains: "In the mid-1990s, after constant changes in band members, the brand of Black Sabbath was in the toilet, and Tony, touring under the name Black Sabbath, was reduced to performing in clubs. Since 1997, when Geezer, Bill and myself rejoined the band, Black Sabbath has returned to its former glory. - It did? Read more here