Editing Demchugdongrub (section)

==Conflict with Yan Xishan==
In August 1936 Demchugdongrub's army attempted to invade eastern Suiyuan, but it was defeated by [[Yan Xishan]]'s forces under the command of [[Fu Zuoyi]]. Following this defeat, Demchugdongrub rebuilt his armed forces and planned another invasion. Japanese agents carefully sketched and photographed Suiyuan's defenses while Demchugdongrub was rebuilding his armed forces.<ref name="Gillin230" />

In November 1936 Demchugdongrub presented Fu Zuoyi with an ultimatum to surrender.  When Fu responded that Demchugdongrub was merely a puppet of "certain quarters" and requested that he submit to the authority of the Chiang Kai-shek's central government, Prince De's Mongolian and Manchurian armies launched another, more ambitious attack. This time Demchugdongrub's 15,000 soldiers were armed with Japanese weapons, supported by Japanese aircraft, and often led by Japanese officers. (Japanese soldiers fighting for Mengguguo were often executed by Chinese forces after their capture as illegal combatants, since Mengjiang was not recognized as being part of Japan).<ref>[[#Gillin1967|Gillin (1967)]], pp. 230–234</ref>

In anticipation of this attempt to take control of Suiyuan, Japanese spies destroyed a large supply depot in [[Datong]] and carried out other acts of sabotage. Yan Xishan placed his best troops and most able generals, including [[Zhao Chengshou]] and Yan's son-in-law, [[Wang Jingguo]], under the command of Fu Zuoyi. During the month of fighting that ensued, the army of Mengguguo suffered severe casualties.  Fu's forces succeeded in occupying Bailingmiao on 24 November 1936, and was considering invading [[Chahar Province|Chahar]] before he was warned by the [[Kwantung Army]] that doing so would provoke an attack by the Japanese Army. Demchugdongrub's forces repeatedly attempted to retake Bailingmiao, but this only provoked Fu into sending troops north, where he successfully seized the last of Demchugdongrub's bases in Suiyuan and virtually annihilated his army.  After Japanese were found to be fighting in Demchugdongrub's army, Yan publicly accused Japan of aiding the invaders. Yan's victories in Suiyuan over Japanese-backed forces were praised by Chinese newspapers and magazines, other warlords and political leaders, and many students and other members of the Chinese public.<ref>[[#Gillin1973|Gillin (1973)]], pp. 234–236</ref>

Demchugdongrub withdrew to Chahar and again reconstructed his army with Japanese help. By the time that the [[Second Sino-Japanese War]] began, in July 1937, his army consisted of 20,000 men in eight Cavalry Divisions. The forces under his command participated in [[Operation Chahar]] and the [[Battle of Taiyuan]], when the Japanese and Mongol forces finally captured most of Suiyuan province.

The Mengjiang United Autonomous Government ({{lang|zh-Hant|蒙疆連合自治政府}} ''Méngjiāng Liánhé Zìzhìzhèngfǔ'') was set up in 1939 with Demchugdongrub first being the vice-chairman, then the chairman. In 1941 he became chairman of the Mongolian Autonomous Federation.