Famous songwriter and musician for the heavy metal bands Black Sabbath and Heaven & Hell. He was among the first bassists to use the wah-wah pedal.
His activism spilled over into a boycott campaign against Fortnum and Mason's for carrying foie grass in their inventory.
He began playing alongside fellow bandmate and good friend Ozzy Osbourne in the 1960s.
He was inspired by writer Aleister Crowley and musician John Lennon during his formative years.
His family was Irish Catholic. He married Gloria Butler, the manager of Heaven & Hell.