The Kamakura Shogunate defeated the Mongols — and bankrupted itself doing it

In 1274 and again in 1281 the Yuan dynasty sent massive invasion fleets against Japan. The Kamakura Shogunate under Hōjō Tokimune chose total mobilisation: it called up samurai from every province, strengthened coastal defences, and kept a large standing force ready for years. Both invasions were repelled, partly by samurai resistance and partly by typhoons that destroyed the Mongol fleets.

The victory was real but the accounting was brutal. The Shogunate had spent its reserves and could not distribute captured land or plunder to the warriors who had answered the call. In a feudal system where service was rewarded with land, a war that produced no new territory was a war that produced no loyalty. Samurai who had borrowed to equip themselves returned home empty-handed.

Tokimune and the Hōjō regents never solved the fiscal hole. They could not tax the court nobility or the great religious estates enough to cover the debt, and further demands on the provinces bred resentment. The Shogunate that had saved Japan from invasion slowly lost the means to govern it. In 1333 it was overthrown.