In 1431, after the 11th head, Morimi OUCHI, was killed in a battle against the Otomo clan and the Shoni clan in Chikuzen Province, a conflict over the succession arose within the Ouchi clan.
1431年、第11代当主・大内盛見が大友氏・少弐氏と戦って筑前国で敗死した後、大内氏内部では後継ぎをめぐっての争いが起こった。