The Japanese “Kamikaze” (Divine Wind) that saved the country from an amphibious invasion by the Mongolian hordes. The Mongols captured a foothold on some outlying Japanese islands, and started to attack the mainland. The Japanese army pushed them back, and they had to retreat to China. When they did, a typhoon ravaged their navy and sank their ships.

The Mongolians, (probably reasonably) seeing this as a fluke, decided to rebuild and attack again. Seven years later. Unfortunately for them, the Japanese fortified their coastline. After basically months of sailing around seeking a place to land, ANOTHER typhoon struck their fleet and destroyed them.

There would be no third invasion.