The Genko War
After repelling the Mongol invasion of Japan a second time in 1281, with the grace of the Divine Wind, the Samurai sent the Shogunate of Kamarura the bill (the Emperor was just a figurehead at the time) but the cupboard was bare. Instead, the Samurai received a scroll of written appreciation. Having spent money and lives on the defense of Japan the grumbling began. Now the grumbling has turned into outright civil war. The Samurai are going to win this war, putting the city of Kamarura to the flames and returning imperial power to the actual Emperor, Go-Daigo in 1333.   
This Year on Wikipedia
Year 1331, Wikipedia.
- Kamakura Period (1192 - 1333)
- The Mongol Invasions of Japan in 1274 and 1281: Kublai Khan vs. the "Divine Winds" by Kallie Szczepanski
- Genko War - Wikipedia, 2014 [last update]