And Campbell – who was fired by Dio in 1986 – asserts the move to reclaim material he co-created is long overdue. He tells Classic Rock: "I've got a different way of looking at it now than I've had for almost 30 years.

"I was fired, then I was portrayed as the one who'd turned my back on the band. It wasn't true: I never wanted to leave Dio," he said. "I will admit that, at the time, I was experiencing growth and I wanted to try different kinds of music.

"That obviously rubbed Ronnie the wrong way. Perhaps that's what he construed as me not wanting to be in the band – but I certainly did not want to leave."