Ōnin War

The was a civil war in Japan. It lasted 10 years, starting in 1467 and ending in 1477.
Hosokawa Katsumoto and Yamana Sōzen had a conflict that grew into a war throughout the country. The Ashikaga shogunate and some daimyo in many regions of Japan fought in this war. 
The conflict was the beginning of a very long struggle to dominate all of Japan.