Once the Second World War had broken out, it soon became clear that morale would be crucial in the military effectiveness of our armed forces. And so was born the Entertainment National Services Association, or ENSA - to send the nation's best singers, dancers, musicians and comedians, from Noël Coward to Gracie Fields, to entertain the troops, however far away they might be. Over the course of the war ENSA gave their first break to such postwar stars as Tommy Cooper and Frankie Howerd, as well as enshrining the young Vera Lynn forever as the forces' sweetheart. When Allied troops landed in Normandy in 1944, George Formby followed close behind, while a distinguished troupe under Laurence Olivier was performing Shakespeare to British soldiers in Hamburg within weeks of the German surrender. Now, Andrew Merriman has talked to surviving ENSA veterans from Vera Lynn to Dame Beryl Grey, to piece together the extraordinary adventures of the ordinary men and women sent out across the world - even to inhospitable, dangerous Burma - whose contribution to the war effort was song, dance and laughter.