Whaam Roy Lichtenstein - architect of Pop art, connoisseur of the comic strip, master of irony and prophet of popular culture. From exhilarating images of ice-cool jet pilots in dog fights, to blue-haired Barbie dolls drowning in scenes of domestic heartache, Lichtenstein's instantly recognisable paintings, with their Ben-Day dots and witty one-liners, defined the art of a generation. But how did a jobbing, unassuming painter of the Fifties become...