In 'Nuremberg: The Translator’s Tale', I uncover the remarkable story of a German-Jew working face-to-face with the Nazi leaders who destroyed his world. Available today: bit.ly/3Ms1Qep @YaleBooks

By the autumn of 1942, aircrews were reporting that the existing maps were simply too small to be of real practical use in the field. In response, MI9 authorised an entirely new series of escape and evasion maps. The printing plates were produced by Kodak, and for the remainder of the war these maps continued to be refined and issued. They were usually numbered, with those carrying the prefix “43” believed to have been printed in 1943. Printed at a main scale of 1:1,000,000, they included larger detailed inserts at 1:250,000 to 1:500,000 and covered vast areas of Europe, from Spain to Holland and Portugal to Turkey. In 1943 and 1944, MI9 produced these maps in enormous quantities so that they could be issued as standard equipment to operational aircrew and ground forces – especially in the weeks leading up to D-Day. For men trapped behind enemy lines in the fierce fighting that followed the Normandy landings, such maps were often the difference between capture and survival. Disorientated, exhausted, and cut off from their units after days of intense combat, a good escape map could mean the difference between finding their way back to Allied lines or being hidden and sheltered by brave local families until they could reach safety. More in my MI9 book: amzn.to/3DFObMd

I visited the Tir National in Brussels where so many brave agents were shot across two world wars, including British nurse Edith Cavell and her colleague Philippe Baucq: