During the Western Han Dynasty, the territory of China began to expand westward, and the eastern and western cultures began to merge and communicate, which represented that China gradually stepped out of the Yellow River basin and began to spread Chinese culture to the west and southwest.
The Yuan Dynasty was the most extensive dynasty in China's history, but I think that although it promoted national integration to a certain extent, the Yuan Dynasty included the early Mongolian Empire, and its ruling knowledge in many territories depended on its powerful military strength, but it did not actually rule it.