In 1206, Temujin held a congress at the source of the Nan River to proclaim the establishment of the Mongol State, and Temujin was revered as Genghis Khan. After the establishment of Mongolia, the road to external expansion was opened. It successively destroyed the surrounding Regimes of Western Liao, Western Xia, Jin, Dali, Southern Song Dynasty, and Tubo. While the Mongols destroyed the surrounding regimes, they also carried out three western expeditions. Through three western expeditions, the Mongol armies fought all the way to Palestine and Central Europe.
Over the course of seventy years, Genghis Khan and his descendants conquered most of Eurasia. The territory of the Mongol Empire reached 33 million square kilometers, and some traditional ancient civilizations were included in the territory of the Mongol Empire, such as the ancient Two Rivers Valley and the Persian region. After Kublai Khan succeeded to the throne, the unified Mongol Empire gradually split, forming the Yuan Dynasty and the Four Khanates. Although the four khanates were independent, they were still nominally respected by the Yuan Dynasty. At that time, the Mongol Yuan Empire occupied most of Asia, but we also saw that some regions were not included in the Mongolian Yuan's territory, such as Vietnam, the Korean Peninsula, Japan and other regions.
The size of the Korean Peninsula is not large, and the terrain is far less complex than that of the Qinghai-Tibet Plateau and the Pamir Plateau. Why didn't the Mongolian Yuan include the Korean Peninsula in its territory? In fact, the reasons are not complicated.
The situation on the Korean Peninsula is different from that of Vietnam and Japan. At that time, the Mongolian Yuan army once attacked Vietnam and Japan on a large scale, but for various reasons, it was fruitless. Japan and the mainland are separated by the sea, and the elite cavalry of the Mongolian Yuan cannot cross the sea to defeat Japan. The weather in Vietnam was too hot, and the Mongolian cavalry had difficulty adapting to such a hot weather. The Korean Peninsula is not so hot, and there is no sea as a barrier. Naturally, it was difficult to stop the Mongol army.
War against Korea had already been waged long before the Mongols destroyed the Jin Dynasty. From 1231 to 1273, the Mongols fought a forty-year war with Korea, seven wars before and after. After seven wars, the Mongol Yuan army finally conquered Korea. At that time, the Goryeo royal family was forced to surrender and became a vassal state of Mongwon. The king of Goryeo needed to marry a princess from Mongolia and become the "donkey state" of the Mongolian Yuan. In addition, the Goryeo Dynasty also had to fulfill the "six things" and the obligations of tribute women, tribute eunuchs, and so on to Mongyuan. As compensation, Mong won gave Goryeo some autonomy, such as retaining the royal family, political power, and army. Although the Goryeo royal family was in many ways restricted by the Mongol Yuan, it retained the state and power.
It is not accurate to say that the Mongolian Yuan did not conquer the Korean Peninsula. The Mongolian Yuan army has truly and completely conquered the Korean Peninsula, and after the war, the Mongolian Yuan has also firmly controlled the Korean Peninsula. Although Goryeo was an "independent" country, it was restricted by the Yuan Dynasty in many ways. If the Yuan Dynasty so wished, it could include the Korean Peninsula in its central territory. The Yuan Dynasty once established the Province of Zhengdong in the Korean Peninsula. Judging from the specifications, there is no difference between the DPRK region and the hinterland. In fact, there are still many differences between zhengdong province and the remaining ten provinces.
The establishment of the province of Zhengdong was mainly to conquer Japan, and Daru Huachi had a pivotal position in the Korean Peninsula, and to some extent can be regarded as the "Emperor Taishang" of the Goryeo Dynasty. The Yuan Dynasty held the Korean Peninsula firmly in control for most of the time until the outbreak of the Peasant Revolt at the end of the Yuan Dynasty. After the outbreak of the peasant revolt at the end of the Yuan Dynasty, the Yuan Dynasty itself was difficult to protect, and naturally it could not take care of the Korean Peninsula.
In 1356, the Goryeo Dynasty purged the pro-Yuan faction in the dynasty, captured the Yuan Dynasty's Shuangcheng Governorate and Helan Province, and abolished the Zhengdong Province. By this time the Goryeo Dynasty had become a de facto independent state, with only nominal vassal relations with the Yuan Dynasty. After the fall of the Yuan Dynasty, the newly established Joseon Dynasty on the Korean Peninsula became a vassal state of the Ming Dynasty.
The Mongolian Yuan has completely conquered the Korean Peninsula and can completely incorporate it into the mainland, but the Mongols have "released" Korea and only made it their own vassal state, thus having the "illusion" that the Mongolian Yuan did not conquer the Korean Peninsula. The Mongolian yuan did not include the Korean Peninsula in its territory, in fact, for many reasons.
There have been many regimes on the Korean Peninsula, and the Central Plains Dynasty has also set up counties and other institutions in parts of the Korean Peninsula. Regimes on the Korean Peninsula relied on the Chunghara Dynasty for most of their survival. For a long time, the regime on the Korean Peninsula was a vassal state of the Central Plains Dynasty. After the establishment of the Goryeo Dynasty, it became a vassal state of Liaojin and other regimes. The Korean Peninsula regime has become accustomed to becoming a vassal state of the Central Plains Dynasty, and the Central Plains Dynasty has long been accustomed to having the vassal state of Korea.
After the establishment of the Mongolian Yuan, especially after the unification of the Central Plains, it naturally regarded itself as an orthodox regime. After the establishment of the Yuan Dynasty, it was also necessary to establish its own vassal state system. The four khanates were effectively independent, but with the Yuan Dynasty as their suzerainty or as a vassal state of the Yuan Dynasty. After the Yuan Dynasty unified China, large-scale conquests basically stopped. For the surrounding regimes, they can also be conscripted, and if they cannot be conscripted, they will try to incorporate them into the system of vassal states. As a traditional vassal state of the Central Plains Dynasty, the Korean Peninsula was naturally the first choice of the Yuan Dynasty. Rather than being included in the territory, the Yuan Dynasty preferred to make the Korean Peninsula a vassal state.
The Central Plains Dynasty conquered the Korean Peninsula many times, such as the Sui Emperor, Tang Taizong, and Tang Gaozong. In its long-term confrontation with the Central Plains regime, the Korean Peninsula regime has summed up a whole set of "ways to survive." If they found that they could not defeat the Central Plains army, they would abandon the capital and flee to several small islands to continue fighting. Exchanging space for time eventually dragged down the Central Plains regime. If they really can't fight, they will choose to surrender, completely admit it, and agree to the various conditions of the Central Plains Dynasty. The land in North Korea is barren and has little practical value, so instead of turning it into a county, it would be better to call it a county. When the Mongol Army came, the strategy of the Goryeo Dynasty was no different from before, and after resistance, it completely confessed.
Long before Mong won and Goryeo fought, Mong won and Goryeo had established contact. Knowing the ferocity of the Mongol army, Goryeo decided to defect to the Mongol army, which had helped fight against the remnants of the Khitan and Jin dynasties. When Mong won attacked Japan, Koryo made it as convenient as possible. The various practices of the Goryeo Dynasty won the "hearts" of the Mongols, and Kublai Khan developed a great affection for Goryeo. Perhaps out of retribution and out of favor, after Kublai Khan established the Yuan Dynasty, he did not include the Korean Peninsula in his territory, but only made Goryeo a vassal state.
If the Mongolian yuan wants to use the Korean Peninsula as a springboard to attack Japan, it needs a stable base. If the Mongolian Yuan includes the Korean Peninsula in its territory, it is very likely to cause a revolt among the people on the Korean Peninsula. At that time, the base may be unstable. If the Goryeo regime is retained, it can use this puppet regime to stabilize the Goryeo people and make full use of the human, material, and financial resources of the Korean Peninsula to support its war against Japan. In peacetime, the resources of the Korean Peninsula can also be fully utilized. For Mong Won, the cost of county-based Korean counties was higher than that of feudal states.
From 1206, the Mongol Yuan began to expand on a large scale, establishing a huge Mongol Empire. But by the time of Kublai Khan, the massive expansion of the Mongol Yuan was basically over. The four khanates gradually began to localize and consolidate vested interests. The Yuan Dynasty devoted its main energies to attacking the Southern Song Dynasty in an attempt to unify the world. After the fall of the Southern Song Dynasty, the scale of the Yuan Dynasty's military began to shrink. With the exception of the conquest of Japan and Vietnam, the use of foreign troops was largely stopped. Mongols and Goryeo fought a war that lasted for more than forty years, and although Goryeo was eventually defeated, it successfully survived the craziest phase of Mongol expansion. By the time Goryeo surrendered, Mong won had entered the era of Kublai Khan.
Compared with the previous Mongol Khans, Kublai Khan had a more strategic vision and paid more attention to buying people's hearts. If Goryeo had not persisted until Kublai Khan ascended the throne, the Korean Peninsula would most likely have been included in the Mongol Empire. Goryeo also used his own efforts to win the chance to survive.