Founded by the Mongols, the Yuan Dynasty was the first unified dynasty established by ethnic minorities in Chinese history. The foreign wars of the Mongol armies were of a conscriptive character, and the two wars against Japan were aimed at conquering Japan and subjugating it. In the 13th century, Mongol cavalry swept across Eurasia, but Japan, which was alone and isolated, did not submit to the Yuan Dynasty, and began to strengthen the defense of Kyushu, the territory closest to Goryeo in Japan (Gao at this time claimed to the Yuan), and was therefore the most likely place to be invaded first- Kyushu.
In 1266, Kublai Khan sent emissaries to Japan, but because of the strong wind, the envoys could not reach Japan, and later sent several times, Japan was very unfriendly to the envoys of the Yuan Dynasty, one of which also withheld the Goryeo guide, Kublai Khan was very angry, in 1274, Kublai Khan ordered Batulu to lead the Mongol Han army of fifteen thousand people to japan. The war was very successful at the beginning, but because of the remote operation, the Yuan army was not familiar with the environment, and the Japanese army adopted guerrilla tactics, and the Yuan army had to prepare to retreat, and in the process of returning to the sea, it encountered a storm, and the result was almost completely destroyed.
The battle line of the Yuan Dynasty was too long, the territory was too large, and the Mongols had finally become a super empire across eurasia, and the elite troops of the Mongols were a total of fifty or sixty, and they had to be stationed in various key places. Finally, the policy of not respecting the famous ethnic groups, the navigation technology of the Southern Song Dynasty was already very advanced, but the Yuan Dynasty did not take advantage of this, listing the Southern Song people as inferior, so there was no expert in navigation and did not serve the Yuan Dynasty.
Of course, the problems of the Yuan army were also very large, in addition to being unfamiliar with naval warfare, the hasty preparation led to shoddy construction of ships, which was also a very important reason (ships were built by the Goryeo people, backward technology and complaints, and the quality was extremely poor).