Inner Mongolia was Never a Part of China
Inner Mongolia, as a part of the Great Mongol Empire, was never a part of China. From the day Genghis khan founded the Great Mongol Empire in 1206 to the death of the last Grand Khan of the Mongols---Ligdan Khan in 1634, the Mongol nation had been an independent state for more than 400 years.
During the Ming Dynasty of China (1368-1644), there were many wars between the Mongols and the Chinese trying to rule over each other, but China's dominance had never reached beyond the Great Wall. Once the Mongols even captured an Emperor of China. (In 1449, Esen Taiji defeated a Chinese army near Peking and took Chinese emperor Ying-tsung (or Ying Zong) prisoner). Also during the Ming dynasty, fearing the Mongol invasion, China took great efforts to rebuild the Chinese ancient fortification ---the " Ten thousand miles of " Great Wall. The Mongol Empire lasted outside of the Great Wall until the Jorchid (later known as Manchu) people took over the entire Inner Mongolia in 1634.
During the Manchu rule, the Mongols never had given up their effort to get rid of the Manchu domination to reestablish an independent Mongolia. Galdan Boshogtu (1645-1697) of Dzungar Mongol once succeeded to unite all the Dzungar Mongols (or western Mongols) and the Khalkha Mongols (Outer Mongols) and almost seized Peking, the Capital of the Manchu Empire.
In 1644, Manchu people succeeded in controlling China and Emperor Shuen-chih (or Shun-Zhi) proclaimed the Great Ching Empire (Tai Ching). So we have enough reason to say that Mongolia was not a part of China during this historical period because Mongolia (Including Inner, Outer, Dzungar Mongols) and China were both ruled by a foreign nation during the time of Manchu Empire. Chinese people didn’t have their own state or government, and China, just like Mongolia, was a part of the Empire established by the Manchu people.
In 1911, following the collapse of the Manchu Empire, there was a great chance for Mongols to be a united independent state once again. However, the Chinese warlords, took the advantage of the Mongol nation’s weakness at that time, tried to take the Mongols under their rule. After 10 years of strive, Outer Mongolia (or Khalkha Mongol) proclaimed their independence in 1921 as People's Republic of Mongolia. But Inner Mongolia, a major part of the Mongol land, was under the Chinese warlords’ tight control and hundreds of years of dream as an independent nation was unable to come true for millions of Mongols living in Inner Mongolia. It is injustice and outrageous that the Chinese, as soon as they gained their freedom, turned to rule other nation.
Since China’s takeover of Inner Mongolia, millions of peasants were settled to Inner Mongolia. Excessive cultivation backed by the warlords turned the great grassland into vast desert. The Mongols, totally depended on the grassland to survive, were forced to abandon their homeland and move to remote places. Meanwhile, those people who held courage to fight for the freedom of their homeland eventually fell down under the guns of the invaders and buried into their beloved land. (Gada Meiren, "Shineh Lama "--- Uljijirgal and Togtokh Baator were the most famous heroes among them).
Demchegdongrov (or De Wang, Teh Wang), however, almost succeeded in establishing an independent Inner Mongolia. Born as a direct descendent of Genghis Khan, he dedicated his whole life to establish a self-ruling, even an independent Inner Mongolia. On July 26,1933, De Wang held his first Conference on Inner Mongolian Self-rule, declared the Inner Mongolian government as a highly self-ruling government. This self -ruling government lasted until 1945. By the end of the WWII, to force the Japanese to end the War, the Soviet-Mongolian joint army entered into Inner Mongolia and then the Soviet Union decided the fate of Inner Mongolia. Despite the Inner Mongolians expressed strong will to be an independent country, or even willing to merge with Mongolia (Outer Mongolia), Joseph Stalin handed Inner Mongolia over to China.
On May 1, 1947, the Chinese Communist Party declared their first puppet Autonomous Region--- the current Inner Mongolian Autonomous Region after the PLA took control over most part of the Inner Mongolia. Since then, the Inner Mongolians suffered the most brutal rule they had ever experienced:
It is very clear that Inner Mongolia was never a part of China and, in fact, China never fairly treated the Inner Mongolians as a part of their own people.