Christel Van Iseghem was sitting in a radio studio when she heard the last words of her great uncle Norbert, murdered by the Nazis for his role in the Belgian resistance. “My heart stood still,” said the 71-year-old from Kallo in Flanders. “This was something I didn’t know existed. I sat there shaking, my hands trembling … It means so much to me. He will not be forgotten.” Before his execution in Munich on 27 October 1944, alongside his friend Noël Boydens, 19-year-old Norbert Vanbeveren wrote to his parents that he felt “a kind of peace and satisfaction in my...