The Battle of Nanjing began after the fall of Shanghai in October 9, 1937, and ended with the fall of the capital city of Nanjing in December, 1937 to Japanese troops, a few days after the Republic of China Government had evacuated the city and relocated to Chongqing. The Nanking Massacre followed the fall of the city. The actual scene of this massacre is introduced in detail in the documentary film of the movie The Battle of China.
General Tang Shengzhi was given the job of defending Nanjing following the retreat of the Chinese Army following the Battle of Shanghai. In a press release to foreign reporters, he announced the city would not surrender and would fight to the death. The defense force blocked roads, ruined boats, and burnt nearby villages, preventing many citizens from evacuating. However, the defense plan fell apart from the very beginning because the defenders were overwhelmed by Chinese troops fleeing from previous defeats such as the Battle of Shanghai, and these troops just wanted to escape to safer ground and refused to obey any orders. As Chiang Kai-shek and his staff such as Chen Cheng had realized, Chinese elite troops could not risk annihilation in a hopeless but symbolic defensive battle in the capital, so in order to preserve these forces for future battles, most of them were withdrawn. General Tang Shengzhi gathered about 100,000 soldiers, mostly untrained, including a few defeated troops from the Shanghai battlefield, to defend the capital. He also placed the 35th and 72nd divisions at the port to prevent people from fleeing Nanjing, as instructed by Chiang Kai-shek's general headquarters at Wuhan. However, the government left Nanking on December 1, and the president left on December 7. Nanjing was left to an International Committee led by John Rabe.
On December 9, after occupying the nearby countryside and demanding a surrender (which was refused), the Japanese troops under Lt. Gen. Asaka Yasuhiko (filling in for Gen. Iwane Matsui) launched a massive assault on the city. Low morale, fleeing troops, and an overwhelming enemy caused the Chinese commanders to order a retreat across the Yangtze River by the evening of December 12. Many orders given during the battle contradicted those of headquarters, and many more orders were simply ignored. This complication, in addition to the inadequate preparatory measures made before the battle, gave little chance for Chinese soldiers to escape.
On December 13, the 6th and 114th Divisions of the Japanese Army first entered the city. Simultaneously, the 9th Division entered nearby Guanghua Gate, and the 16th Division entered Zhongshan and Taiping Gate. That same afternoon, two small Japanese Navy fleets arrived on both sides of the Yangtze River. Nanking fell to the Japanese by nightfall.
In the following six weeks, the Japanese troops committed the Nanking Massacre.
Several cities, including Xuzhou and Wuhan soon fell after this battle. The government also tried to slow down the advancing Japanese by causing the 1938 Huang He flood, which covered three provinces.