Ma Hongbin
In 1937, the Empire of Japan openly and fully invaded Republic of China by war. On 8 December 1937, Mongolian Prince Demchugdongrub (also known as "De Wang") declared an independence of the remaining parts of Inner Mongolia (i.e., the Suiyuan and Chahar provinces) as Mengjiang, and signed an agreements with Manchukuo and Japan. Its capital was established at Zhangbei (now in Hebei province), with the Japanese puppet government's control extending as far west as the Hohhot region. The Japanese advanced was defeated by Hui Muslim General Ma Hongbin at the Battle of West Suiyuan and Battle of Wuyuan. After 1945, Inner Mongolia has remained part of China.