博多湾
Mongol emissaries first arrived in 1268, and all the samurai armies of Kyūshū was mobilized in anticipation of the first of the Mongol invasions of Japan, which came six years later. Kublai Khan's forces seized Tsushima and Iki Island before landing on the shores of Hakata Bay on November 19. The invaders were eventually repelled, and extensive fortification efforts were undertaken in the ensuing years. The second invasion arrived in 1281, and was similarly repelled. Though referred to in Japanese as the battles of Bun'ei and Kōan (文永と弘安の役), both of these invasion attempts are frequently referred to in English sources as the "Battle of Hakata Bay."