Battle of Shanghai

Bazi Bridge, mid-afternoon

Fighting began on 13 August 1937 near the Japanese Naval Landing Party headquarters and at Bazi — Eight Character — Bridge in northern Shanghai. Contemporary accounts disagree about which side fired first; the Tokyo tribunal record notes that the Japanese and Chinese versions contradicted one another.

Around 3 p.m., troops of China's 88th Division under Major Yi Jin reached the bridge, fired on a Japanese detachment establishing positions there, and took it. Japanese artillery then shelled the Chinese troops.

From skirmish to artillery battle by nightfall

The U.S. consul general, Clarence E. Gauss, reported artillery fire in northeastern Shanghai from 4 p.m.; by 8 p.m. it had spread toward the civic-center area.

By late afternoon two Japanese warships in the Huangpu River were shelling Chinese positions.

The troops initially engaged on the Japanese side were naval infantry — about 3,000 personnel reported as responsible for guarding roughly 30,000 Japanese residents.

What the 13th was not

The Ōyama incident of 9 August — the disputed death of a Japanese naval sub-lieutenant near Hongqiao airfield — raised tension sharply, and about 30 Japanese warships concentrated at Shanghai within roughly 48 hours. But the tribunal found its details contradictory and observed that Japan did not cite it to justify the later campaign.

A Joint Commission meeting on 12 August produced mutual promises not to attack, and no settlement.

Chiang Kai-shek's larger coordinated air and ground offensive came on 14 August; 13 August is conventionally and officially treated as the battle's opening, and Japan announced on 15 August that two army divisions would be dispatched.