For details on the battle fought between the Muromachi shogunate and Yoshihiro OUCHI, who was a shugo daimyo (shugo, which were Japanese provincial military governors, that became daimyo, which were Japanese feudal lords) in 1399, refer to the Oei War.
応永6年（1399年）に、室町幕府と守護大名大内義弘との間で戦われた戦いについては、応永の乱を参照のこと。