Above these two maps is an abrupt horizontal line. What, didn't you draw it all? Increase your knowledge! I see. If you want to check the map of our country, people generally take Tan Qixiang's Atlas of Chinese History as the standard map. However, although this version of the map is highly credible, there are still many unclear places, which are all caused by the uncertainty of historical map drawing.
Because painters can't visit that dynasty in person and observe it on the spot, they can only collect information from other historical materials, which inevitably brings subjectivity when drawing maps, so sometimes they are biased. However, the straight line we are talking about today is not due to the negligence of the draftsman, but to other reasons. Although the maps of Yuan Dynasty and Ming Dynasty are the same straight line, they represent different meanings.
On the map of the Yuan Dynasty, we can see something behind this straight line, that is, there is a small map at the lower left, representing the northern part of Siberia, which was also the territory of the Yuan Dynasty at that time. From here, we can also see how vast the territory of the Yuan Dynasty was. Since it is obvious
Since we know this area belongs to, why not mark it on the map? Originally, this area was not drawn directly because of its high dimension, cold climate and small population, and almost no population in the border areas, which made it difficult to map on the spot.
Moreover, this cold land belongs entirely to the Yuan Dynasty. Although few people set foot on it, the Yuan Dynasty enjoyed absolute control over it. So we only need to mark it a little on the map, and we don't need to draw it all, which is similar to the expression of the South China Sea Islands on our map now. The map of the Ming Dynasty is another case. There is a straight line in the northeast of the map of the Ming Dynasty. This is not because there are no mapping points, but because it is difficult to determine the boundary and accurate scope.
When the Ming Dynasty was first established, there was a headquarters in this place. At that time, the people who lived in this land were jurchen, and the name of this headquarters was the Nuer Tuotu command post. Because the specific location of the Jurchen nationality can't be verified, and a certain range can't be sketched, so we can only draw a straight line.
In order to show that this is the territory of the Ming Dynasty, in addition, because the territory is also dynamic and may increase or decrease with the passage of time, the scope is not clearly defined, but replaced by a straight line.