During the Nanjing Massacre (1937–1938), Bernhard Arp Sindberg from Denmark, together with his colleagues, provided shelter for about 20,000 Chinese civilians, protecting them from Japanese atrocities. Although Sindberg's actions in Nanjing saved many lives, he remained unmarried and rarely spoke of this experience for the rest of his life. In an interview, his niece Mariann Arp Stenvig reflected on the extraordinary yet little-known story left behind by her uncle.