When it comes to the unified and powerful dynasties in China's history, people often talk enviously about Qin and Han Dynasties, Sui and Tang Dynasties or Ming and Qing Dynasties. The Yuan Dynasty established by 127 1 was ignored because of the short dynasty time and the policy of ethnic estrangement. But in fact, the Yuan Dynasty inherited the development trend of China's unification of multi-ethnic countries since the Qin and Han Dynasties, with a vast territory beyond the Han and Tang Dynasties, and achieved a wide range of ethnic blending, which laid a solid foundation for the reunification of the next hundreds of years, and its historical contribution can not be ignored. Kublai Khan named this country "Dayuan" on the advice of counselor Liu, which comes from the phrase "Daizai" in Zhouyi. According to Yuan people's explanation, its main meaning is "big". This highlights the grandeur of the political ideals of the rulers of the Yuan Dynasty. Historically, the Yuan Dynasty was a multi-ethnic empire based on the military government. During its rule of 100 years, it has always maintained the stability of the Central Plains and its borders, and has always maintained a vast territory. As a riding nation different from the landlord regime of the Han nationality in the Central Plains, it is not easy. This is an achievement achieved through hard work. Although the Yuan Dynasty took some measures to govern multi-ethnic countries, it also made very useful explorations and contributions.

? The territory of the Yuan Dynasty, "North" surpassed the northern Yinshan Mountain, the west quicksand, the east Liao left and the South China Sea, and surpassed the Han and Tang Dynasties. Yong Zhengdi once said, "A unification of China began in Qin Dynasty; The unification beyond the Great Wall began in the Yuan Dynasty, which has revealed the historical contribution of the Yuan Dynasty to the formation of China's territory. In the early Ming Dynasty, Yuan history was compiled, and it was believed that all the so-called powerful dynasties in China's history, such as Han, Sui, Tang and Song, had serious border problems, while Yuan dynasty was rare. Therefore, "the heyday of Han and Tang dynasties is not as good as Yan." The Yuan Dynasty had a vast territory and many nationalities, and the situation in the border areas was generally stable, which benefited from more effective territorial governance. An important measure of territorial governance in the Yuan Dynasty was to move the capital. With the advancement of the unified war, the territory of the Yuan Dynasty was expanding day by day, and the number of nationalities it ruled was also increasing. Continuing to locate the capital in the hinterland of grassland is not conducive to the effective governance of multi-ethnic countries. Kublai Khan realized that it was imperative to move the capital and moved the capital of Mongolia to Dadu (now Beijing). Another important measure of territory management in Yuan Dynasty was to attach importance to the construction of post stations. An efficient postal delivery system can ensure the smooth traffic between the central government and the border areas, and the decrees of the central government can reach all places quickly. As the territory of the Yuan Dynasty surpassed that of the Han and Tang Dynasties, the post stations extended further to the frontier than the previous generation, and the post stations as far away as extreme areas helped to strengthen the control of the central government over various places. The effectiveness of territorial governance in Yuan Dynasty is also closely related to positive institutional innovation. The Yuan Dynasty followed and improved the provincial system of the Jin Dynasty, thus effectively strengthening the central government's management of the border areas. During the Han and Tang dynasties, the central government implemented the policy of detaining the northeast and southwest, and many areas did not pay taxes or register their household registration. In the Yuan Dynasty, "taxes are now levied, which is better than that in the mainland". The Yuan Dynasty also established Zheng Xuanyuan according to the political and social characteristics of Tibet and other places, which strengthened the central government's overall jurisdiction over local politics, economy and religion. In the southwest, Lingnan and other border areas, propaganda and appeasement departments are set up to coordinate local military and political affairs and strengthen military defense. The Yuan Dynasty also followed the inspection department in the Song and Jin Dynasties and strengthened the management of grassroots society in border areas. For example, the Penghu Inspection Department is responsible for the management of islands such as Penghu and Taiwan Province Province. These border control systems and measures have far-reaching influence in the history of China, and they are mostly used by later generations.