One of the tunes on The Book of Souls is a tribute to the Mrs. Doubtfire star, who took his own life last year (14) following a long battle with depression.

In an interview with Italian newspaper Corriere Della Sera, frontman Bruce Dickinson says, "My favourite song (on the album) is one I didn't write. It's Tears of a Clown, which talks about Robin Williams. I ask myself how could he be so depressed when he always seemed to be so happy."

The Book of Souls is set to be released on 4 September (15).