The gates opened, then they closed. In the narrow space between those two actions on the evening of July 26, 1937, any remaining hope of preventing full-scale war between China and Japan collapsed at the Guang'anmen gate of Beiping. The incident lasted less than an hour, but it gave Japan the pretext it needed to abandon diplomacy and launch a military assault on the ancient capital. It came just nineteen days after the Marco Polo Bridge Incident had ignited the first shots of what would become the Second Sino-Japanese War, and one day after fighting at Langfang had pushed both sides to the edge.
By late July 1937, Beiping was a city caught between converging forces. The Chinese 29th Army had massed troops at Baoding and Shijiazhuang to the south and at Datong in Shanxi, effectively surrounding the Japanese garrison in the Fengtai District. On the Japanese side, freshly mobilized units from the Kwantung Army and the Japanese Korean Army were moving toward Tianjin and Beiping. The Hebei-Chahar Political Council, a semi-autonomous Chinese administrative body that governed the region, found itself trying to manage a situation that had already moved beyond anyone's control. Every gate in the old city walls had become a potential flashpoint.
Major Hirobe's 2nd Battalion of the 2nd China Garrison Infantry Regiment had orders to move 26 trucks of soldiers to Japanese barracks inside Beiping's walls, ostensibly to protect Japanese residents. Takuro Matsui, head of the Japanese Special Service Agency, had negotiated passage through Guang'anmen with the Hebei-Chahar authorities, and the city's mayor, Qin Dechun, had approved it. But when Major Tokutaro Sakurai arrived at approximately 6:00 PM to coordinate the passage, Chinese guards kept the gate sealed. Negotiations dragged on for ninety minutes before the gates finally opened around 7:30 PM. The first three trucks passed through. Then Chinese soldiers opened fire on the column. Two-thirds of the convoy made it inside before the gate slammed shut, splitting Hirobe's force in two -- some trapped inside the city, some stranded outside under fire.
The Japanese command responded with an ultimatum. They withdrew a prior request that both armies pull back to defined positions and instead sent word directly to Song Zheyuan, the head of the Hebei-Chahar Political Council and commander of the 29th Army, that Japan considered the ambush at Guang'anmen an unforgivable insult to its military. The Japanese further advised the Chinese to withdraw all forces from Beiping to spare the city the destruction of the coming battle. Two days later, on July 28, Japanese forces launched their assault against Chinese positions around Beiping, while Chinese troops attacked in Tianjin at midnight. The Battle of Beiping-Tianjin was over in two days. For the soldiers who died on both sides of the Guang'anmen gate that July evening, the war that followed would consume eight years and millions of lives.
Located at 39.9139N, 116.3920E in central Beijing. The original Guang'anmen gate no longer stands, but the site is in the southwestern portion of old Beijing, near modern Guang'anmen neighborhood. The Forbidden City is approximately 2 km to the northeast. Beijing Capital International Airport (ZBAA) is approximately 30 km northeast. The area is now a dense urban district with no visible remnants of the old city wall at this location.