East-West Battle of Harima


Akamatsu Masanori

Harima Province

Akamatsu Clan

Date:  Meiō 8 (1499)

Location:  Harima Province

Outcome: Uragami Murakuni led a failed revolt against Uragami Norimune who supported Akamatsu Yoshimura as the successor to Akamatsu Masanori as head of the Akamatsu clan.

The East-West Battle of Harima  (Tōzai-toriai kassen) occurred in 1499.  This was an internal revolt led by Uragami Murakuni against Uragami Norimune as a chapter in a succession struggle within the Akamatsu clan after a long period of governance by Akamatsu Masanori.  The term is associated with the temporary division of Harima Province between east and west as a result of the conflict.


Akamatsu Masanori served as a powerful sengoku daimyō governing the provinces of Harima, Mimasaka, Bizen and one-half of Kaga.  He further served as the ninth head of the Akamatsu clan over an extended period from 1458 to 1496.  Following his sudden death from illness in 1496, Akamatsu Yoshimura (Masanori’s son-in-law) became his successor as the tenth head of the Akamatsu clan.  However, owing to Masanori’s sudden death, Yoshimura’s succession may not have been a result of the wishes of Masanori as much as those of senior retainers who wielded power in the Akamatsu clan at the time, including Uragami Norimune, Bessho Noriharu, Kodera Norimoto, Yakushiji Takayo, and Akamatsu Norisada.  While Yoshimura was young at the time of his succession, his wife, Komeshi, was eighteen when Yoshimura was adopted by Masanori, and Yoshimura is believed to have been a similar age. 

Nevertheless, the abrupt end of Masanori’s term led to confusion within the clan, resulting in an internal conflict over the issue of succession, known as the Harima Disturbance (Banshū no sakuran) or Katsunori’s coup d’état.  During this event, Norimune, a clan elder and deputy military governor, supported Yoshimura, while Uragami Murakuni backed Akamatsu Katsunori.   Finally, Masanori’s widow (Tōshō-in) and adoptive mother of Yoshimura, aligned with Bessho Noriharu.  Noriharu was concerned that if Yoshimura became the successor, Norimune would take advantage of his youth to become further autocratic, so it was premature to grant full authority to Yoshimura.  Therefore, he recommended that Tōshōin serve as the interim head with the backing of Hosokawa Masamoto until Yoshimura matured.

Course of events

In 1499, Uragami Murakuni joined with Akamatsu Katsunori against Uragami Norimune in a revolt known as the East-West Conflict (Tōzai-toriai kassen).  At one point, Murakuni garnered control of eight districts in eastern Harima.  Norimune narrowly escaped owing to a valiant defense by Ukita Yoshiie, taking Yoshimura to Shioya Castle held by Uno Masahide.  While providing shelter to Norimune, Masahide backed Yoshimura as the successor.  Masahide then directed Tōji Sakyō-no-suke to attack Murakuni, while Masahide himself went to Kyōto to request mediation by Hosokawa Masamoto, the deputy shōgun, and an Imperial edict for a cessation of hostilities from Ashikaga Yoshizumi, the eleventh shōgun.  The family members eventually reconciled, with Yoshimura becoming the successor. Masahide died on 10/25 of 1502 at age of eighty-one, while Tōshōin continued to serve an influential role in the clan alongside Yoshimura.