The period from 1467 to 1590 in Japan was known as the Warring States period. During this time, Japan was ravaged by war as samurai lords battled each other for territory and influence over the Imperial court. It’s the era that made samurai into legends, immortalized in the films of Kurosawa Akira.
Although the Imperial court held onto the ceremonial trappings of government, real power had long since passed into the hands of the shogun—a military leader nominally appointed by the Emperor. By the 13th century, a series of ineffective shoguns combined with growing economic pressures had caused the shogun’s influence to wane, leaving powerful samurai warlords free to pursue their own ambitions.