Shimizu Muneharu

Who They Were

Shimizu Muneharu (清水宗治, しみず むねはる) was a samurai commander who lived from 1537 to 1582, during the late Muromachi period. He is remembered chiefly for the manner of his death: he took his own life by seppuku to end the Siege of Takamatsu, allowing the army besieging his castle to disengage and march east to avenge Oda Nobunaga.

Muneharu served the Mōri clan, one of the dominant powers of western Japan, as a retainer under the command of Kobayakawa Takakage. He was also known as Shimizu Chōzaemon (清水長左衛門). His father was Shimizu Munenori, and he had at least two sons, Shimizu Muneyuki and Shimizu Kageharu.

Life and Career

Muneharu was born in 1537, in the sixth year of the Tenbun era (天文, てんぶん). He was lord of Shimizu Castle in Bitchū Province, in the western part of the main island of Honshu. In 1565 he captured Bitchū Takamatsu Castle and became its lord, holding both strongholds in the province.

He took part in the Mōri campaigns to unify the Chūgoku region, the long western stretch of Honshu, fighting as a retainer to Kobayakawa Takakage. Through the 1560s and 1570s the Mōri expanded and defended their territory against rival houses, and Muneharu's castles in Bitchū placed him on the front line where Mōri lands met those of their enemies.

That front line became critical in 1582. Hashiba Hideyoshi, a senior retainer of Oda Nobunaga, advanced into the Chūgoku region as part of Nobunaga's drive to reunify Japan. Muneharu shut himself inside Bitchū Takamatsu Castle and resisted. Hideyoshi offered surrender terms: if Muneharu handed over Bitchū Province, his life would be spared. Muneharu refused.

Hideyoshi then flooded the castle. He diverted the nearby river and built embankments so that the water rose around Takamatsu Castle, leaving the defenders stranded and the fortress on the verge of falling. In June 1582, while the castle was still under water, Nobunaga was killed in the Incident at Honnōji in Kyoto. Word of his death reached Hideyoshi, who needed to break off the siege and move quickly east. Hideyoshi made peace overtures on one condition: that Muneharu commit seppuku. Muneharu agreed, and died on 23 June 1582.

Why They Matter

Muneharu's death is bound up with one of the most consequential weeks in Japanese history. When Nobunaga died at Honnōji, Hideyoshi was deep in Mōri territory with an army committed to a siege. If the Mōri learned of Nobunaga's death before Hideyoshi could act, they could have destroyed his army, and Hideyoshi would never have been able to march east and defeat Akechi Mitsuhide at the Battle of Yamazaki.

Muneharu's seppuku let Hideyoshi end the siege cleanly and turn his army around. He kept the news of Nobunaga's death from the Mōri long enough to conclude terms, and then moved fast. The settlement at Takamatsu is therefore one of the hinges on which Hideyoshi's rise to power turned. Muneharu, by accepting the terms, gave up his life and his castle and made that march possible.

For the Mōri, the loss of Bitchū Takamatsu and the peace settlement marked the limit of their expansion eastward. Hideyoshi went on to complete the unification of Japan, and the Mōri survived as a major domain under the Tokugawa order that followed. Muneharu's own house did not share in that survival in any prominent way; his name is attached instead to the castle and the act.

The Name in Japanese

The full name is written 清水宗治.

• Romaji: Shimizu Muneharu
• Kana: しみず むねはる
• Family name: 清水 (しみず, Shimizu)
• Given name: 宗治 (むねはる, Muneharu)

Character by character:

清 — read here as し (shi). It means "clear", "pure", or "clean". It appears in many Japanese words and names connected with clarity and purity.

水 — read here as みず (mizu). It means "water". Together, 清水 (しみず) means "clear water" or "spring water", and it is a common Japanese surname as well as an ordinary word. The reading しみず rather than せいすい is the kun'yomi, the native Japanese reading, which is the usual one for this surname.

宗 — read here as むね (mune). It means "doctrine", "sect", "origin", or "ancestor", depending on context. In personal names it is a common element, and it appears in the names of Muneharu's father Munenori and his sons Muneyuki and Kageharu.

治 — read here as はる (haru). It means "govern", "rule", or "cure/heal". As the final element of a given name it is extremely common in samurai names, often paired with a first element to form a two-character name.

So the name as a whole reads as a place-derived surname, "Clear Water", plus a two-character given name, 宗治, built from a name element 宗 and the very common name-ending 治. The alternative name Shimizu Chōzaemon (清水長左衛門) follows a different pattern: 長左衛門 is a conventional male name of the type used in the period, ending in 左衛門 (さえもん, saemon), which derives from a court office title and was widely used as a name element.

Legacy

Shimizu Muneharu's grave is at Seikyō-ji, in Hikari, Yamaguchi Prefecture, in the old Mōri heartland of western Honshu. The temple preserves his memory as a retainer who died for his lord's house and, in the event, for the settlement that let Hideyoshi's army withdraw.

His story is inseparable from Bitchū Takamatsu Castle and the flood that reduced it. The siege is remembered as a textbook case of water used as a weapon, and Muneharu as the commander who chose to die by his own hand rather than see his garrison destroyed. The date of his death, 23 June 1582, places it within days of Nobunaga's death and at the start of the sequence of events that carried Hideyoshi to national power.