When did Genghis Khan Temujin return it after he occupied all parts of Asia and Europe in the Yuan Dynasty?

First of all, Temujin is not from China, and he has never been ruled by China. He only rebelled under the rule of Jurchen, and didn't value the ruling skills of Han civilization in Yuan Dynasty, because Yuan had seen enough Central Asian civilization before entering the Central Plains, unlike other northern nationalities who only saw the splendid civilization in the Central Plains and immediately sinicized it as soon as they entered the Central Plains. The royal family of Yuan Dynasty has never been sinicized, which gives people the impression that it has always regarded itself as it.

Similarly, it has not been returned. The empire of the Yuan Dynasty is vast, stretching to Sakhalin Island in the east, the Arctic Circle in the north, the South China Sea in the south and Central Asia today in the west. Obviously, at the level of productivity at that time, it was impossible to rule such a large area. On the contrary, it adopts the method of divide and rule. They have a unified emperor, the monarch of the Yuan Dynasty. As the representative of the empire, Temujin's descendants established many khanates as vassals below, which was bigger than the gold in the north. Obviously, as a country without a strong civilization, it will be assimilated by local religions. Therefore, the direct rule of the Yuan Empire is only the Mongolian Plateau and its southern region.