Second Sino-Japanese War: Japan declares Nanking capital of a new Chinese puppet government, nominally controlled by Wang Jingwei.

The Second Sino-Japanese War was fought between the Republic of China and the Empire of Japan between 1937 and 1945, following a period of war localized to Manchuria that started in 1931. It is considered part of World War II, and often regarded as the beginning of World War II in Asia. It was the largest Asian war in the 20th century and has been described as The Asian Holocaust, in reference to the scale of Japanese war crimes against Chinese civilians, similar to the European ones. It is known in China as the War of Resistance Against Japanese Aggression.

Nanjing is the capital of Jiangsu, a province in East China. The city, which is located in the southwestern corner of the province, has 11 districts, an administrative area of 6,600 km² (2,500 sq mi), and as of 2021 a population of 9,423,400. Situated in the Yangtze River Delta, Nanjing has a prominent place in Chinese history and culture, having served as the capital of various Chinese dynasties, kingdoms and republican governments dating from the 3rd century to 1949, and has thus long been a major center of culture, education, research, politics, economy, transport networks and tourism, being the home to one of the world's largest inland ports. The city is also one of the fifteen sub-provincial cities in the People's Republic of China's administrative structure, enjoying jurisdictional and economic autonomy only slightly less than that of a province. It has also been awarded the title of 2008 Habitat Scroll of Honor of China, Special UN Habitat Scroll of Honor Award and National Civilized City. Nanjing is also considered a Beta city classification, together with Chongqing, Hangzhou and Tianjin by the Globalization and World Cities Research Network, and ranked as one of the world's top 100 cities in the Global Financial Centres Index.

The Reorganized National Government of the Republic of China, commonly described as the Wang Jingwei regime, was a puppet state of the Empire of Japan in eastern China. It existed coterminous with the Nationalist government of the Republic of China under Chiang Kai-shek, which was fighting Japan alongside the other Allies of World War II. The country functioned as a dictatorship under Wang Jingwei, formerly a high-ranking official of the Kuomintang (KMT) party. The region it administered was initially seized by Japan during the late 1930s at the beginning of the Second Sino-Japanese War.