We all know that ancient China was a country with a vast land and a vast wealth, which in itself is not in doubt, but due to the lack of historical materials, in fact, the mapping of Chinese dynasties is full of controversy, especially the border areas between several countries in Europe and Asia, to calculate that these countries have once given the Chinese feudal dynasty a tribute, in a broad sense, these places are Chinese places, but after all, they have not been established and effectively managed, which has a lot of trouble for future generations how to determine the territory.
Compared with the Han and Tang Dynasties, the most inaccurate is the Territory of the Yuan Dynasty, although the territory of the Han and Tang Dynasties is also very extensive, but according to the central government's administrative agencies for localities, the Western Regions Protectorate during the Han Dynasty is also counted in the Territory of the Han Dynasty, so it has formed a very special display method of the Territory of the Han Dynasty on the map, and the Same Tang Dynasty also interconnected with some countries in Central Asia through the Silk Road, so some regions in Central Asia should also be counted into the Chinese territory.
The territory of the Yuan Dynasty is not easy to determine, since Kublai Khan destroyed the Southern Song Dynasty, the establishment of the Central Plains Dynasty regime began, in fact, in today's Russia, there are still many Mongol khanates, after the death of Genghis Khan, during the reign of Wo Kuotai, once made all the eldest sons expeditions, of which Badu once conquered many countries including Eastern Europe, until the Danube River, if it were not for the death of Wo Kuotai, he would be able to conquer the whole of Europe.
Therefore, under Mongol rule, in addition to inheriting his father's territory, Batu also laid a large area of land, established a Korean Khanate of Chincha, and also divided the territories he occupied to his brothers and established their own khanates, but nominally these khanates should be under the jurisdiction of the Mongol Yuan.
If you calculate it this way, then most of today' russia should be included in the territory of the Yuan Dynasty, after all, after the 16th century, with the rise of Peter the Great, the Mongols ended their rule in Europe, and theoretically, although the Mongolian iron horse did not go deep into the Arctic Ocean, but as long as they wanted to go, they could go, because the Siberia region, including the Arctic Ocean, did not have a regime at that time, and it was considered a landless wasteland.
If the map of the Yuan Dynasty is drawn, if it is not conservative, it can include the southern Part of the Arctic Ocean, including Siberia, and some conservative people believe that it should not be painted this way, and even the khanates established by the Mongol nobles are their own independent regimes and should not be counted in the territory of the Yuan Dynasty. These two views are widely disputed in the field of historiography.
Later, everyone quarreled and finally adopted a compromise approach, that is, when drawing the northern territory of the Yuan Dynasty, it deliberately did not draw the whole picture, but left a straight line, but also to avoid controversy in the academic community, in terms of understanding, we can also include Siberia, or not, in short, depending on their respective understandings.