The Battle of Beiping-Tianjin was fought between the armies of Japan and China in July–August 1937 amid the Second Sino-Japanese War. Following the Marco Polo Bridge incident, Imperial Japanese Army troops occupied the once and future Chinese capital of Beijing.
After the Japanese China Garrison Army attacked the walled city of Wanping in the Marco Polo Bridge incident on 8 July 1937, General Song Zheyuan ordered his forces to hold their positions while attempting to avert war through diplomacy. On 9 July, the Japanese offered a ceasefire if the Chinese 37th Division would be replaced by the less hostile 29th Army, but they repeatedly violated the ceasefire as their own reinforcements arrived. Ma Bufang sent a Turkic cavalry division to counterattack against the Japanese invaders in Beijing as the Japanese attacked Langfang on 25 July. On 29 July, the Japanese collaborationist East Hebei Army mutinied against the Japanese in Tongzhou. However, the Japanese utilized their numerical superiority to conquer Tianjin and Tanggu on 29 July. At the same time, Chiang Kai-shek ordered Song to retreat to Baoding in southern Hebei province, and Beijing was taken on 8 August. The North China Plain was left helpless in the face of Japanese advances, and the National Revolutionary Army was in constant retreat until the Battle of Taierzhuang in 1938.