Mogami Yoshiaki

Mogami Yoshiaki (最上 義光, February 1, 1546 – November 29, 1614) was a daimyō of the Yamagata Domain in Dewa Province, in the late Sengoku and early Edo periods. Known as "Fox of Dewa".[1]

Mogami Yoshiaki
最上 義光
Mogami Yoshiaki.jpg
Mogami Yoshiaki
Head of Mogami clan
In office
Preceded byMogami Yoshimori
Succeeded byMogami Iechika
Daimyō of Yamagata Domain
In office
Succeeded byMogami Iechika
Personal details
BornFebruary 1, 1546
Yamagata Domain
DiedNovember 29, 1614
Yamagata Castle
RelationsMogami Yoshimori (father)
Yoshihime (sister)
Date Terumune (brother in law)
Date Masamune (nephew)
Nickname"Fox of Dewa"
Military service
AllegianceGoshichi no kiri inverted.svg Toyotomi clan
Mitsubaaoi.svg Eastern Army
Tokugawa family crest.svg Tokugawa shogunate
UnitAshikaga mon.svg Mogami clan
CommandsYamagata domain
Battles/warsBattle of Jugorihara (1588)
Siege of Odawara (1590)
Kunohe Rebellion (1591)
Siege of Shiroishi (1600)
Siege of Hasedō (1600)


Mogami Yoshiaki was the first son of Mogami Yoshimori (最上 義守), of the Mogami clan and succeeded his father as daimyō of Yamagata.[1] When Yoshihime, who was his sister, married Date Terumune, the Mogami clan allies with the Date clan. During this time, Yoshihime wrote information about the Date clan to Yoshiaki, her and Yoshiaki's actions made the Date clan distrust the Mogami family. Yoshiaki fought against the Date clan twice in different years, in both battles Yoshihime advanced to the middle of the battlefield to create a peace treaty.[2]

In 1571, Mogami Yoshiaki officially became the head of the Mogami clan.[3]

In 1588, he expanded the Mogami territory enormously in the Shōnai and Semboku areas, and threatened Yoshiuji Daihoji, who sought aid from Honjō Shigenaga at 'Battle of Jugorihara'.

When Toyotomi Hideyoshi came to power, Mogami submitted to his rule, as a result, he was given about 200,000 koku by Toyotomi Hideyoshi after the Siege of Odawara and participated in attacking Kunohe Rebellion. But later Yoshiaki became a supporter of Tokugawa Ieyasu following Hideyoshi's death. He was known to hate the Toyotomi because Hideyoshi ordered the execution of Yoshiaki's teenage daughter when purging his nephew Toyotomi Hidetsugu, to whom Yoshiaki's daughter was engaged. Hideyoshi refused to spare the life of Yoshiaki's 15-year-old daughter, who had only just arrived in Kyoto to become Hidestugu's concubine and had not yet even met her husband-to-be.

In 1600, he battled Uesugi Kagekatsu, an enemy of Tokugawa's, alongside Date Masamune (his nephew), another lord of the far north. Mogami and Date supported Ieyasu at the famous Sekigahara campaign,[4] he aided in Date's siege of Shiroishi, and was then attacked in his own home castle of Hataya, Kaminoyama and Hasedō. After which Mogami's domain was expanded to 570,000 koku in return for his loyal service.[1] This made the Yamagata domain the fifth largest in Japan at the time, excluding the land held by Tokugawa.


He died at Yamagata Castle in 1614.[5] Yamagata maintains the Mogami Yoshiaki Historical Museum, just outside the rebuilt Great Eastern Gate of Yamagata Castle, which displays his helmet, battle command baton and other implements he actually used.


Mogami Yoshiaki laid out and built the castle town, which became the foundation of modern-day Yamagata City. He controlled the "Three Difficult Places" on the Mogami River, making navigation safer from the Sea of Japan to the inland, and bringing the culture of Kyōto and Ōsaka to Yamagata. His dam building projects at Kitadaseki, Inabazeki and other places, and other irrigation control measures helped develop rice cultivation in the Shōnai plain.

Notable vassalsEdit



  1. ^ a b c "朝日日本歴史人物事典「最上義光」の解説". kotobank. Retrieved 24 October 2021.
  2. ^ 泉秀樹 (2003-05-21). 戦国なるほど人物事典: 100人のエピソードで歴史の流れがよくわかる (in Japanese). PHP研究所. ISBN 9784569579450.
  3. ^ a b c "Sakenobe Hidetsuna" (in Japanese). Mogami Yoshiaki Historical Museum official. Retrieved 24 October 2021.
  4. ^ "関ヶ原合戦と最上義光". Mogami Yoshiaki Museum. Retrieved 29 October 2021.
  5. ^ "Mogami Yoshiaki". Mogami Yoshiaki Museum. Retrieved 29 October 2021.
Preceded by
First Daimyō of Yamagata
Succeeded by