Best known for Dad' s Army, in which his Sergeant Wilson played the languid, rakish foil to Arthur Lowe' s pompous, chippy Captain Mainwaring, John Le Mesurier was one of Britain' s favourite and most recognisable character actors.

The epitome of insouciance and languor on screen, in real life this charming, quietly-spoken bon viveur was plagued by private turmoil and heartbreak. Married three times, he saw his first wife succumb to alcoholism, his second - the comedy diva Hattie Jacques - move her lover into the family home, and his third enjoy a passionate dalliance with troubled comic Tony Hancock.

As Graham McCann reveals in this fully authorised and moving biography, as an actor John Le Mesurier was a key ingredient in the success of Britain' s greatest sitcom, but as a man he was far more courageous than Sergeant Wilson was ever meant to be.