Japanese-sponsored puppet government in Chahar and Suiyuan (central Inner Mongolia) under Mongol nobleman Prince Demchugdongrub, formed in 1939 by merging earlier Japanese-backed Mongol autonomous bodies; placed under the Wang Jingwei regime's nominal sovereignty from 1940.
Collapsed with Japan's defeat in August 1945; its territory reverted to Chinese (Republic of China, then PRC) control.
The atlas holds 2 border frames for Mengjiang (Mengjiang United Autonomous Government) — the shape you scrub through changes in 1936 · 1937.
Broader study of Japan's puppet-state strategy in northeast China and Inner Mongolia that produced Mengjiang alongside Manchukuo; no Mengjiang-specific monograph verified on Open Library after several search attempts.