The Mongol forces were immense. The 1281 invasion fleet, assembled from Korea and southern China, is estimated to have been one of the largest in history before the modern era, carrying up to 140,000 soldiers. Japanese defenders, having learned from the 1274 attack, built a stone seawall around Hakata Bay and harassed the fleet for weeks. Recent geological studies of sediment cores from lakes near the invasion sites reveal distinct layers of ocean-derived material, providing physical evidence fo

The Storm That Changed History： The Mongol Invasion of Japan In 1274 and 1281, Kublai Khan — grandson of Genghis Khan and ruler of the vast Mongol Empire — launched two massive invasions of Japan to force the Kamakura shogunate into submission. The first fleet (1274) of around 30,000–40,000 Mongol, Korean, and Chinese troops landed on Kyushu but faced fierce samurai resistance and withdrew after a single day of fighting, partly due to storms and supply issues. The second, far larger invasion (12