Kirsty Young's castaway is the novelist, historian and biographer, Peter Ackroyd. As a child he used to walk the streets of London with his grandmother - an experience that, he believes, fostered his own love for the city. He was appointed literary editor of The Spectator when he was just 23 and has gone on to write dozens of books since. He has written a biography of London, as well as books about people he calls 'cockney visionaries' such as Charles Dickens, Wilkie Collins and, now, Charlie Chaplin. Yet, of the work he's produced so far, he says: "Every book for me is a chapter in the long book which will finally be closed on the day of my death. So that final book is the one which gives me a sense of achievement."Producer: Christine Pawlowsky.