What happened
In 1274 (the Bun’ei campaign), a force of roughly 30,000–40,000 struck Tsushima and Iki and landed at Hakata Bay, withdrew after initial fighting, and lost ships to a storm. In 1281 (the Kōan campaign), two fleets totaling — by traditional counts — some 140,000 men, among the largest seaborne operations before modern times, were held for weeks at Hakata by Japanese coastal fortifications and resistance, then largely destroyed by a typhoon.
Background
Kublai Khan mounted both expeditions from Yuan China, with fleets and crews conscripted from Korea (Goryeo) and China.
Consequences
The expeditions cost the Yuan enormously. In Japan, a defense that could not be rewarded strained the Kamakura shogunate and contributed to its later fall, and the “divine wind” idea echoed into 20th-century myth. Underwater archaeology off Takashima has recovered wrecks and anchors from the 1281 fleet.