The Battle of Shanghai (August 13, 1937 - November 9, 1937) was a major engagement during the Sino-Japanese War.
The battle was signified the beginning of an all-out war, not just some "incidents," between the two countries. The battle lasted three months and involved nearly one million troops, and is divided into three stages. The first stage lasted from August 13 to September 11, during which the Kuomintang army defended the city against the Japanese who were landing at the shores of Shanghai; The second stage lasted from September 12 to November 4, during which the two armies involved in a bloody house-to-house battle in an attempt to gain control of the city; and the last stage, lasting from November 5 to end of the month, involved the retreat of the Chinese army by flanking Japanese. In the battle, approximately 200,000 died on both sides.
On August 13, more than 10,000 Japanese troops pressed towards the Kongkew district of Shanghai and encountered the Chinese Peace Preservation Corps. The Japanese expected a swift victory to conquer Shanghai in three days and China in three months. However, they faced strong resistance.
On August 22, the Japanese 3rd, 8th, and 11th Divisions made an amphibious assault under naval bombardment and proceeded to land in at Chwansa, Shihtzelin, and Paoshan districts of Shanghai. The Chinese were unable to counterattack because of heavy enemy naval firepower.
By September 17, the Chinese retreated to the North Railway Station further inland to set up a defensive line at Lotien-Shuangtsaoten section of the railway. During mid-September vicious house-to-house fighting erupted with 100,000 Japanese troops and the Japanese broke the Lotien line. The Chinese retreated further to the southern bank of Wentsaopang creek and took up defensive positions along the Kwangfu-Szesiangkungmiao-Liuho line.
The Japanese further increased their men to 200,000 during October and launched an offensive on the Wentsaopang creek region. The Chinese also started their counter-offensive. This caused tremendous casualties on both sides. On October 23, the Japanese broke through Chinese lines, forcing them to make an orderly retrograde operation further south in the hilltops of the Blue Dragon Ridge.
The Chinese fought relentlessly to hold their higher ground. But with casualties of some thirty thousand, the Chinese retreated. With Chinese lines faltering throughout the city, the Japanese demanded a surrender on November 7th. However, the Chinese refused to surrender and bitter close-quarters battle continued, with Japanese planes straffing and bombing the city. The last Chinese troops evacuated from the city and retreated further south on November 12.
The Battle of Shanghai was a military defeat but a morale-boosting victory for the Chinese. It made clear to the world that the Chinese would no longer stand by and watch as Japanese forces "peacefully" conquered its territory piece by piece. It also demonstrated that the Chinese would not surrender under intense Japanese fire.