In 1274, the Yuan fleet set out with an estimated 15,000 Mongol and Chinese soldiers and 8000 Korean soldiers in 300 large vessels and 400-500 smaller craft, although figures vary considerably depending on the source. The primary port for the operation was Quanzhou in Fujian, then the center of China's maritime trade.[11] They landed on Komodahama beach on Tsushima Island on October 5, 1274. Sō Sukekuni, governor of Tsushima, led a cavalry unit of 80 to defend the island, but he and his outnumbered unit were killed in the engagement.
The Mongols and Koreans subsequently invaded Iki. Tairano Takakage, the Governor of Iki, fought the invaders with about 100 of his cavalrymen, but he killed himself after his unit was defeated.
The Mongol forces landed on November 19 in Hakata Bay, a short distance from Dazaifu, the ancient administrative capital of Kyūshū. The following day brought the Battle of Bun'ei (文永の役), also known as the "First Battle of Hakata Bay".
The Mongol fleet destroyed in a typhoon, ink and water on paper, by Kikuchi Yōsai, 1847
The Japanese were inexperienced in managing such a large force (all of North Kyūshū had been mobilized), and the Mongols made significant initial progress. It had been approximately 50 years since the last major combat event in Japan (Go-Toba's adherents in 1221), leaving not a single Japanese general with adequate experience in moving large bodies of troops. In addition, the style of warfare that was customary within feudal Japan involved single combat, even on large battlefields.
The Mongols possessed foreign weapons which included superior long-range armaments (the short composite bows that the Mongols were famous for, with poisoned arrows, fire arrows, bow-launched arrows with small rocket engines attached and gunpowder-packed exploding arrows and grenades with ceramic shells thrown by slings to terrify the enemy's horses), and easily had the upper hand in open land combat. The Japanese force at Hakata Bay needed time to await the arrival of reinforcements, with which they would be able to overwhelm the Mongol invaders.
Around nightfall, a typhoon caused the Mongol ship captains to suggest that the land force reembark in order to avoid the risk of being marooned on Japanese soil. By daybreak, only a few ships had not set out to sea. Those that had were destroyed by the storm. Some accounts offer casualty reports that suggest 200 Mongol ships were lost. However, small Japanese boats were much more swift and maneuverable than Mongol ships, and the Japanese were able to board the remaining ships of the crippled Mongol army. The samurai approached and boarded the ships under cover of darkness and fell on the invaders ferociously. In the small confines of the ships, during the predawn darkness, the Mongols (trained as cavalrymen and horse archers) were unable to bring their bows to bear effectively. However, the long, thin Japanese swords got stuck and snapped off in the thick, boiled leather armor of the Mongols, causing Japanese blacksmiths to reevaluate their swords after the first invasion. This led to the beginning of the divergence of the katana from existing tachi swords in the 13th and 14th century.[12]
A story widely known in Japan is that back in Kamakura, Tokimune was overcome with fear when the invasion finally came, and wanting to overcome his cowardice, he asked Mugaku Sogen, his Zen master also known as Bukko, for advice. Bukko replied he had to sit in meditation to find the source of his cowardice in himself. Tokimune went to Bukko and said, "Finally there is the greatest happening of my life." Bukko asked, "How do you plan to face it?" Tokimune screamed, "Katsu!" ("Victory!") as if he wanted to scare all the enemies in front of him. Bukko responded with satisfaction, "It is true that the son of a lion roars as a lion!"[13] Since that time, Tokimune was instrumental in spreading Zen and Bushido in Japan among the samurai.