Kublai Khan ascended the throne in the Central Plains in 1260, and made Beijing its capital in 1264. Shortly thereafter, Koryo was forced to surrender. Two years later, he asked South Korea to send a special envoy to Japan and asked Japan to submit. At that time, Zhao Yi arrived in Japan on behalf of Korea and the Yuan Dynasty. 1268, Kublai Khan sent the second batch of messengers, and they also returned empty-handed. Both groups of emissaries mentioned the implementation of Zhenxi, and Zhenxi conveyed the request to the general of Kamakura shogunate and the Japanese emperor in Kyoto. Since then, Kublai Khan has continued to send a series of letters through the envoys of North Korea or the ambassadors of the Yuan Dynasty, and threatened to wage war. Japan was in the middle of the Kamakura era, and the shogunate, Prince Weikang, had no real power, but the "executive power" was Sejong Kitajima. The shogunate decided not to surrender, and immediately began to strengthen the defense of Kyushu, which is Japan's closest territory to North Korea, so it is also the most likely place to be attacked first. First of all, the shogunate ordered the name of Kyushu to return to his post and moved Kyushu's troops to the west to further strengthen the defense against possible landing points. In addition, the shogunate also organized large-scale prayer activities to deal with the crisis, during which most other government activities were postponed.

1293 Kublai Khan wanted to wage war as early as 1268, only to find that North Korea did not have enough financial resources to provide sufficient army and navy. 1273, he sent an army to North Korea as a pioneer, but as a result, this army could not be self-sufficient in North Korea and was finally forced to return to the Yuan Dynasty for supplies. Because the horses needed by the Yuan army and the pasture for raising horses seriously restricted the action of the troops, so that the Yuan army could not move in almost barren places. 1274 yuan army fleet finally set off. Among them,15,000 Mongolian and Han soldiers and 8,000 Korean warriors took 300 large warships and 400 to 500 small warships. This unit easily occupied Tsushima Island and Yiqi Island, and landed at Hakata Port near Taizaifu, the capital of ancient Kyushu, on 10/19. The next day, there was a battle of Wen Yong, that is, the battle of Hakata Port. Although the Yuan Army was superior in weapons and tactics, their numbers were far less than those of the Japanese samurai who had been prepared for a long time, and these samurai were reinforced after learning that Tsushima Island and Yiqi Island had fallen. Insist on the whole day, the night storm, the yuan army had to withdraw.

Starting from 1275, the shogunate began to prepare for the second invasion that they thought would be carried out soon. In addition to better organizing the samurai in Kyushu, they also built forts and other defense facilities at many possible landing sites, including Hakata Port. At the same time, King Koryo negotiated with the Yuan Dynasty many times and opposed the plan of further aggression against Japan. The Yuan Dynasty also sent envoys to Japan, but Japan twice ordered the envoys sent by the Yuan Dynasty to be beheaded. Kublai Khan was very angry and began to actively plan the second invasion.