As a result, Chinese can only harassed its own citizen, and being conquer by tons of other small countries, how humiliating. History shows that they have never conquer any countries that is as big as they are, they only pick on small countries, simply because that's all the strength they got. Unfortunately, even trying to take over small country like Vietnam sometimes is a wrong choice. That's why Vietnam is still Vietnam today, speak Vietnamese and write Vietnamese and not Chinese. To prove that Chinese culture can only be (as described by Westerner and the Japanese) "the sick man of Asia". Even in modern day, the Chinese government still harassed and abused their own people of freedom and property, Tienanmen Square massacre, the Chinese revolution that killed about 20 millions Chinese by Mao. There's more, but I prove my point. You want to be a winner, then have a winning heritage, as least don't let other countries fuk your country so much into shame.
At the time Mongolian invaded Beijing, Beijing was not under China. It was under Chinese nemesis, Jin Dynasty. Jurchen people were the ruking ethnical group. Jurchen came from Manchuria. They were ancestor of Qing Dynasty. Qing Dynasty eventually assimilated Chinese Han culture. Jin adopted most Chinese system, but Chinese hated them back in 12 and 13th century. Most Han Chinese were treated as slaves. Most Chinese historians stated Chinese lost more than 50% territory to Jin Dynasty. Of course, many Chinese call Jin Dynasty as Chinese because its descendent conquered ann eventually assimilated Chinese culture. This is irony that history books stated the evil invaders, Jin, conquered Northern China, and Jin was the hated enemy of China. You can callJin Chinese just becaus4 the d4sendents become Chinese. Technically, back in 12 and 13th century, like Mongolua, Jin was not Chines4. Beijing was under dynasty. When Mongolia invaded northern, Mongolia wanted to destroyed Jin Dynasty. Chines on the south, Song Dynasty, hated Jin People so much that they supported Mongolia logistically to conquere Jin. Of course, Mongolia enentually conquered China in the south decad4s late5.
The battle in bejing was between Mongolia and jin but not China.
In most of times, China was ruled and enslaved by others. Chinese were enslaved by mongol, manchu, japan, xianbei, Khitan, Jurchen empires.