Mongol invasions of Japan

in 1274 and in 1281 were major military events in Japanese history. Kublai Khan twice tried to conquer the Japanese islands; and his armies failed both times. 
The two failed invasion attempts are important because they were defining events in Japanese history. 
The attempts show the limits of Mongol (Yuan Dynasty) ability to expand the Chinese empire.
Consequences.
After the destruction of the Mongol invaders, Japan's independence was guaranteed. A power struggle within Japan led to the growth of military governments and less Imperial power.