Iron Maiden dedicate new song 'Tears of a Clown' to Robin Williams

'I ask myself how could he be so depressed when he always seemed to be so happy?'

Robin Williams was one of the greatest comic actors of his generation (Getty)

Iron Maiden have revealed that one of their new album's songs is dedicated to the late, great actor Robin Williams.

The British heavy metal group will release The Book of Souls, their first album in five years, next month and frontman Bruce Dickinson says his favourite has a very special meaning.

"My favourite song is one I didn't write," he told Italian publication Corriere Della Sera. "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?'"

Williams tragically took his own life on 11 August last year after a long struggle with depression and addiction.

Dickinson's bandmates guitarist Adrian Smith and bassist Steve Harris penned the track in tribute to Williams. It will be one of 11 songs that run for 92 minutes in total as part of a double album.

Recording was delayed earlier this year when Dickinson underwent treatment for a cancerous growth on his tongue. He has since been given the all-clear but manager Rod Smallwood has told fans that his recovery period means there will be no Iron Maiden gigs until 2016.

In the meantime, fans can get their hands on The Book of Souls from Friday 4 September.