Suiyuan campaign
The Suiyuan campaign began in 1936. Before a single Mongolian soldier crossed the border, an elite Chinese anti-aircraft battalion sent from Nanjing had shot down four Japanese planes in preliminary raids. The Empire of Japan denied any hand in the invasion that followed. Yet Japanese aircraft, artillery, armored cars, and staff officers stood behind it from the start. Two forces carried out the invasion, both founded and funded by Tokyo. They were the Inner Mongolian Army and the Grand Han Righteous Army, and their target was Suiyuan province, then part of the Republic of China. Within weeks the operation collapsed. A poorly trained, demoralized proxy force handed China one of its first clear victories over Japanese-backed troops. Who built these proxy armies, and why did Japan insist it had no part in their defeat? What did that defeat change for a divided Chinese government?
In September 1931, the Mukden Incident gave Japan's Kwantung Army the opening to occupy China's three northeastern provinces outright. The army defeated the forces of Zhang Xueliang, the young warlord known as the 'Young Marshal,' who had governed the region for the Nationalist government. In 1932 the Kwantung Army installed Puyi, the last Qing emperor, as ruler of a new puppet state called Manchukuo. Soon after, Japan folded three eastern Mongolian leagues, ancient regions of Inner Mongolia, directly into that puppet state.
In May 1933, fighting between China and Japan over Manchuria ended with the signing of the Tanggu Truce. The peace did not last. Japan's territorial ambitions persisted, and Chinese public opinion turned firmly against the truce's harsh terms.
In 1929, Japanese agents made contact with Prince Demchugdongrub, an Inner Mongolian nobleman known as De Wang, who wanted greater autonomy from the Kuomintang government in Nanjing. Japan recognized his ambition to build an independent Mongolian state and saw a chance to use it for their own ends. De Wang, in turn, hoped an alliance would bring weapons and training for his own Mongolian Army.
By 1933, the Kwantung Army had made winning over the Mongolian nobility a central priority. Japanese officers exploited the growing friction between Mongolian leaders and the Nanjing government. They pulled De Wang further into their camp, offering weapons and help retaking Inner Mongolia. In 1934, they occupied several more Mongolian leagues and armed the forces of a separate warlord, Li Shouxin, as part of the same plan.
In October 1935, De Wang met Japanese military commanders in Xinjing and struck a formal deal on Japan-Mongolia cooperation. Japan pledged military and financial backing to help him seize Inner Mongolia and eventually build a Mongolian state. That promise became public in February 1936, when De Wang proclaimed the Mongol Military Government in a grandiose ceremony. The new government adopted the birthday of Genghis Khan as its calendar. De Wang swore an oath 'to recover the original land of the Mongols, and to complete the great mission of national revival.' At its founding the state controlled only the northern Chahar province, but plans to push into neighboring Suiyuan were already underway.
Japanese intelligence operatives spent several months working inside Suiyuan to lay the groundwork before the invasion. The Inner Mongolian Army that carried it out drew on troops loyal to De Wang and other Mongolian nobles, joined by assorted Chinese collaborators. Its main force numbered about 10,000 men, split into eight divisions, and it was poorly armed.
Li Shouxin's Mongol detachment was drawn from the Manchukuo Imperial Army and attached to De Wang's command. It was relatively well armed and decently trained, unlike the rest of the coalition. The warlord Wang Ying, hired directly by the Kwantung Army, brought a third force called the Grand Han Righteous Army, about 6,000 strong. His men were bandits recruited in haste, and their disunity and lack of training badly damaged morale across the whole coalition.
Japan tried to compensate for its allies' weakness by supplying weapons and embedding small groups of advisers inside every collaborationist unit. Artillery, aircraft, and armored cars backed them up. On the other side stood the Chinese Nationalist 35th and 19th Armies, along with local forces, roughly 45,000 men in total. That force outnumbered the combined Mongolian Army and Grand Han Righteous Army by a wide margin.
The invasion began in October 1936, led by the troops of De Wang and Wang Ying, while Li Shouxin's detachment held back in reserve. Nationalist and Inner Mongolian forces first clashed at the town of Hongort on the 14th of November. A major Mongolian assault the next day was repulsed by the Chinese defenders. Over the following days the attackers kept storming the town's walls, but each attempt was beaten back with heavy losses. Mongolian troops fought with courage but lacked training for that kind of assault. A final attempt on the 16th of November, launched during a snowstorm, failed as well.
On the 17th of November a Chinese counterattack caught the invaders off guard and sent them retreating in disorder to their headquarters at Bailingmiao. General Fu Zuoyi's 35th Army seized the opening, swinging west of Bailingmiao before striking the base directly. Chinese troops opened with suicide attacks, then broke through the city gates using trucks. They drove the Inner Mongolian 7th Cavalry Division out of Bailingmiao and inflicted heavy losses. Mongol casualties ran from three hundred to nine hundred killed, with three hundred wounded and three hundred taken prisoner.
The Chinese haul at Bailingmiao included bags of flour, cans of petrol, rifles, machine guns, motor vehicles, and field guns. That capture marked the end of the Mongolian Army's push into Suiyuan, though the province itself was far from settled.
News of the Bailingmiao victory spread fast, and China celebrated it as a turning point. It was the first time the Chinese army had stopped a Japanese-backed force outright, and the story stunned the international press. Delegations traveled from as far as the southern Chinese provinces to urge the Suiyuan defenders to keep fighting.
Chinese officials pointed to the captured trucks, artillery, rifles, and machine guns as proof of Japan's hand in the invasion. Hachiro Arita, Japan's foreign minister, denied it flatly: 'Japan was not involved in this conflict in Suiyuan at all.' The Xi'an Incident soon followed, pushing the Kuomintang and the Chinese Communist Party to recognize Japan as the greater threat. The two rivals agreed to work together against Japan, a shift thought to be partly influenced by events in Suiyuan.
Small-scale fighting dragged on in Suiyuan province for months after Bailingmiao. It did not stop until the Marco Polo Bridge Incident in July 1937 opened full-scale war between China and Japan.
Prince Demchugdongrub retreated to northern Chahar after the Bailingmiao defeat, his army gutted by losses he now had to replace. Japan drew up new regulations to sharpen the force's performance and opened a fresh recruitment drive. By 1937, De Wang's rebuilt army numbered 20,000 men across eight cavalry divisions.
That rebuilt force fought in Operation Chahar and the Battle of Taiyuan. In those campaigns, Japanese regulars and their Inner Mongol allies finally captured eastern Suiyuan province. The Chinese photographer Fang Dazeng documented the region during this period, and his images of the warzone now sit in the National Museum of China.
Common questions
What was the Suiyuan campaign?
The Suiyuan campaign was a 1936 attempt by the Inner Mongolian Army and the Grand Han Righteous Army, both founded and supported by the Empire of Japan, to take Suiyuan province from the Republic of China. It happened shortly before the Second Sino-Japanese War and ended in defeat for the Japanese-backed forces.
When did the Suiyuan campaign take place?
The invasion began in October 1936, with the heaviest fighting occurring in November 1936 at Hongort and Bailingmiao. Small-scale fighting continued in Suiyuan for months afterward, lasting until the Marco Polo Bridge Incident in July 1937.
Who commanded the Japanese-backed forces in the Suiyuan campaign?
Prince Demchugdongrub, known as De Wang, commanded the roughly 10,000-strong Inner Mongolian Army. Wang Ying led the Grand Han Righteous Army of about 6,000 men, while Li Shouxin commanded a better-armed and better-trained detachment held in reserve.
Why did the Suiyuan campaign fail?
The Suiyuan campaign failed mainly because of poor training and low morale among the Mongolian and collaborationist troops. General Fu Zuoyi's Chinese 35th Army exploited this weakness, routing the invaders at Bailingmiao on the 17th of November 1936.
What happened at the Battle of Bailingmiao during the Suiyuan campaign?
Fu Zuoyi's 35th Army flanked the Mongolian headquarters at Bailingmiao, broke through the gates with trucks after suicide attacks, and drove out the Inner Mongolian 7th Cavalry Division. The Mongols lost three hundred to nine hundred men killed, three hundred wounded, and three hundred captured, along with trucks, artillery, and other supplies.
Did Japan admit involvement in the Suiyuan campaign?
No. Japan's foreign minister, Hachiro Arita, said 'Japan was not involved in this conflict in Suiyuan at all.' Chinese forces pointed to captured Japanese trucks, artillery, and other equipment as evidence contradicting that denial.