The Marco Polo Bridge incident, also known as the Lugou Bridge incident or the July 7 incident, was a three-day battle that began on 7 July 1937 in the district of Beijing between the 29th Army of the National Revolutionary Army of the Republic of China and the Imperial Japanese Army.
Since the Japanese invasion of Manchuria in 1931, there had been many small incidents along the rail line connecting Beijing with the port of Tianjin, but all had subsided. On the night of 7 July, Japanese garrison troops at Lugouqiao held an unusual manoeuvre; and, alleging that a Japanese soldier was missing, demanded entry into the City of Wanping to conduct a search. Fighting broke out while the Japanese complaint was still under negotiation. However, the missing Japanese soldier had already returned to his lines. The Marco Polo Bridge incident is generally regarded as the start of the Second Sino-Japanese War.
Introduction
In English, the battle is usually known as the "Marco Polo Bridge incident". The Marco Polo Bridge is an eleven-arch granite bridge, an architecturally significant structure first erected under the Jin dynasty and later restored during the reign of the Kangxi Emperor of the Qing dynasty in 1698. It gained its Western name from its appearance in Il Milione, Marco Polo's record of his travels.
It is also known as the "Lukouchiao", "Lugouqiao", or 'Lugou Bridge incident' from the local name of the bridge, derived from a former name of the Yongding River. This is the common name for the event in Japanese (蘆溝橋事件, Rokōkyō Jiken) and is an alternate name for it in Chinese and Korean (Korean: 노구교 사건; RR: Nogugyo Sageon). The same name is also expressed or translated as the "Battle of Lugou Bridge", "Lugouqiao", or "Lukouchiao".
Background
Tensions between the Empire of Japan and the Republic of China had been heightened since the Japanese invasion of Manchuria in 1931 and their 1932 creation of a puppet state, Manchukuo, with Puyi, the deposed Qing dynasty emperor, as its head of state. After the invasion, Japanese forces extended their control further into northern China, seeking to obtain raw materials and industrial capacity. A commission of inquiry from the League of Nations published the Lytton Report which was critical of the Japanese, resulting in Japan quitting the League.
The Kuomintang (KMT) government of China refused to recognize Manchukuo but did agree to the Tanggu Truce with Japan in 1933. Subsequently, there were various "incidents", or armed clashes of a limited nature, followed by a return to uneasy peace. The significance of the Marco Polo Bridge incident is that, following it, tensions did not subside again; instead, there was an escalation, with larger forces committed by both sides and fighting spreading to other parts of China. With hindsight, this small incident can, therefore, be regarded as the start of a major conflict.
By the terms of the Boxer Protocol of 7 September 1901, China had granted nations with legations in Beijing the right to station guards at twelve specific points along railways connecting Beijing with Tianjin. This was to ensure open communications between the capital and the port. By a supplementary agreement on 15 July 1902, these forces were allowed to conduct maneuvers without informing the authorities of other nations in China.
By July 1937, Japan had expanded its forces in China to an estimated 7,000 to 15,000 men, mostly along the railways. This number of men, and the amount of concomitant matériel, was several times the size of the detachments deployed by the European powers, and greatly in excess of the limits set by the Boxer Protocol. By this time, the Imperial Japanese Army had already surrounded Beijing and Tianjin.
Incident
On the night of 7 July, the Japanese units stationed at Fengtai crossed the border to conduct military exercises. Japanese and Chinese forces outside the town of Wanping—a walled town 16.4 km (10.2 mi) southwest of Beijing—exchanged fire at approximately 23:00. The exact cause of this incident remains unknown. When a Japanese soldier, Private Shimura Kikujiro, failed to return to his post, Chinese regimental commander Ji Xingwen (219th Regiment, 37th Division, 29th Army) received a message from the Japanese demanding permission to enter Wanping to search for the missing soldier; the Chinese refused.
Private Shimura had merely lost his way and was found shortly thereafter. (He claimed to have sought immediate relief in the darkness from a stomach ache and become lost; according to Peter Harmsen, he had visited a brothel.) The Chinese authorities were notified of his return at around 2:00 a.m. the following morning. However, despite the soldier being found, the Japanese military decided to escalate their demands. Because shots had been fired at their troops during the initial entry into Wanping, they shifted the purpose of their mission from a search for Shimura into a hunt for the Chinese soldiers who had fired the initial shots. While Japanese diplomats and the Special Service Agency in Peiping attempted to negotiate a peaceful local settlement, the Japanese garrison headquarters in Tianjin sent firm instructions to the front lines ordering troops to demand a formal apology for the shooting and to prepare to use force. By that time both sides were mobilizing, with the Japanese deploying reinforcements to surround Wanping. The Chinese defenders were equally resolute. He Jifeng, commander of the 110th Brigade (who historians later discovered had secret contact with the Chinese Communist Party), ordered the 219th Regiment to closely monitor the Japanese and to counterattack if provoked.
Later that night, a unit of Japanese infantry attempted to breach Wanping's walled defenses but were repulsed. An ultimatum by the Japanese was issued two hours later. As a precautionary measure, Qin Dechun, the acting commander of the Chinese 29th Army, contacted the commander of the Chinese 37th Division, General Feng Zhi'an, ordering him to place his troops on heightened alert.
At 02:00 on 8 July, Qin Dechun, executive officer and acting commander of the Chinese 29th Army, sent Wang Lengzhai, mayor of Wanping, alone to the Japanese camp to conduct negotiations. However, this proved to be fruitless, and the Japanese insisted that they be admitted into the town to investigate the cause of the incident.
At around 04:00, reinforcements of both sides began to arrive. The Chinese also rushed an extra division of troops to the area. At 04:45 Wang Lengzhai had returned to Wanping, and on his way back he witnessed Japanese troops massing around the town. Within five minutes of Wang's return, a shot was heard, and both sides began firing.
Colonel Ji Xingwen led the Chinese defenses with about 100 men, with orders to hold the bridge at all costs. The Chinese were able to hold the bridge with the help of reinforcements, but suffered tremendous losses. At this point, the Japanese military and members of the Japanese Foreign Service began negotiations in Beijing with the Chinese Nationalist government.
A ceasefire agreement was reached on 11 July in Beiping, negotiated primarily by Chinese General Song Zheyuan, commander of the 29th Army and chairman of the Hebei-Chahar Political Council, alongside representatives Zhang Zizhong and Zhang Yunrong. The formalized three-point agreement stipulated that:
- The Chinese would express regret and punish those responsible.
- The Chinese would turn over the defense of Wanping Fortress to the civilian Peace Preservation Corps.
- China would take preventative countermeasures and crack down thoroughly against anti-Japanese organizations, specifically citing the Communist Party and the Blue Shirts Society.
Despite this signed agreement, Japanese Garrison Infantry Brigade commander General Masakazu Kawabe initially rejected the truce and, against his superiors' orders, continued to shell Wanping for the next three hours, until prevailed upon to cease and to move his forces to the northeast.
Aftermath
Although a local ceasefire had been declared, efforts to de-escalate the conflict ultimately failed. The Japanese army leadership, backed by Prime Minister Fumimaro Konoe's populist "initiative theory," continued to push for mobilization and stirred up public war fever, deliberately overturning earlier non-escalation policies and renaming the skirmish the "North China Incident". Fighting quickly resumed, driven by a deep mutual distrust and a lack of control over frontline forces. The closer the Chinese troops of the 29th Army were to the front lines, the stronger their anti-Japanese sentiment became. Because of this localized fury, even though Song Zheyuan and other senior Chinese officers ordered a compromise with Japan, they could not fully control their own battalions.
Escalation by the Central Governments
While local forces skirmished, the central governments in Tokyo and Nanjing both made decisions that inadvertently sabotaged the chances of a lasting peace. In Tokyo, the Imperial Japanese Army General Staff was initially divided. The non-expansionist faction, led by Major General Kanji Ishiwara, strongly argued against escalating the conflict in China, insisting that Japan's primary strategic focus needed to remain on preparing for a potential war with the Soviet Union. Ishiwara successfully pushed for Imperial Order No. 400 on 8 July, which explicitly instructed Japanese forces in China to avoid further use of military force. However, as local negotiations stalled and reports emerged of Chinese troop movements, hardliners within the Japanese military gained traction. Fearing a Chinese offensive, Tokyo authorized the mobilization of several divisions from mainland Japan. On 11 July, in accordance with the Goso conference, the Imperial Japanese Army General Staff authorized the deployment of an infantry division from the Chosen Army, two combined brigades from the Kwantung Army and an air regiment composed of 18 squadrons as reinforcements to Northern China. By 20 July, total Japanese military strength in the Beiping-Tianjin area exceeded 180,000 personnel. This decision severely undermined the local Japanese commanders attempting to negotiate a localized settlement and sent a threatening signal to the Chinese.
Simultaneously in Nanjing, Generalissimo Chiang Kai-shek determined that Japan's expanding presence in North China could no longer be tolerated. Rather than allowing the regional 29th Army to handle the crisis independently, Chiang ordered Central Army divisions to march north towards Baoding and Shijiazhuang to reinforce the front lines. Under the He–Umezu Agreement of June 1935, Nanjing's Central Army forces had been prohibited from entering Hebei Province. Chiang's deployment of these divisions directly into Hebei violated the treaty and was an unprecedented intervention, as the central government had never directly deployed troops to Hebei while bound by the agreement. This massive deployment confirmed the Japanese hardliners' worst fears, and in response, the Japanese military command in Tianjin decided to temporarily break off the ceasefire negotiations and press for a full-scale offensive against the Chinese forces to implement the He-Umezu Agreement. Chiang firmly solidified this stance on 17 July during a gathering of prominent figures from Chinese society at Lushan. In the Lushan Statement, Chiang publicly called for a war of total resistance against Japan, declaring that the Marco Polo Bridge Incident had called into question the existence of the nation as a whole and that China had finally reached its absolute limit of endurance regarding Japanese encroachment.
Meanwhile, the Chinese Communist Party capitalized on the escalating crisis to advance the formation of the Second United Front. The CCP's declaration for KMT-CCP cooperation, which called for a united resistance to aggression, was sent to the Nationalist government on 15 July 1937. However, the document had already been drafted by Zhou Enlai on 4 July—three days before the outbreak of hostilities at the Marco Polo Bridge. This timeline indicates that the incident was not the direct cause for the CCP's political proposals for cooperation.