Originally from Hamburg, John Rabe had moved to China in 1908 and spent most of the following decades there as a representative of the Siemens company. When the Japanese military began its attacks on the city, Rabe decided to remain in Nanjing. Together with other foreigners, he formed the International Safety Zone and served as its chairman. In this position as ‘de facto mayor’ of Nanjing, he helped save thousands of Chinese from death of starvation, cold, or atrocities committed by the Japanese military (‘Nanjing Massacre’). […] This research project seeks to contribute to the scholarly debate about war diaries as historical sources, problems of witnessing, and contested war memory.