I have three half-metre-square maps of southern Europe framed on my living-room wall. Printed by the American air force on acetate rayon – lightweight, waterproof and hard to tear – the ‘handkerchief maps’ were given to my father-in-law, Howard Walker, who flew with the Australian Air Force during the Second World War. He started operational flying from Brindisi in October 1944, in Lancaster bombers that dropped supplies – guns, explosives, food and clothing – for partisans in northern Italy, Yugoslavia and northern Greece. ‘My job,’ he says, ‘was to ride up in the perspex nose of the plane to pick out landmarks of any sort that would help the navigator affirm or correct the plane’s course.’...