was a daimyō

Daimyo

is a generic term referring to the powerful territorial lords in pre-modern Japan who ruled most of the country from their vast, hereditary land holdings...

 of the Yamagata domain

Yamagata Domain

Yamagata Domain was a Japanese fief , located in Dewa province, in the Tōhoku region . Modern-day Yamagata Prefecture is roughly contiguous with the domain, and its capital city, also called Yamagata, grew up out of the daimyo's castle town...

 in Dewa Province

Dewa Province

is an old province of Japan, comprising modern-day Yamagata Prefecture and Akita Prefecture, except for the city of Kazuno and the town of Kosaka. It was sometimes called .-Historical record:...

, in the late Sengoku period

Sengoku period

The or Warring States period in Japanese history was a time of social upheaval, political intrigue, and nearly constant military conflict that lasted roughly from the middle of the 15th century to the beginning of the 17th century. The name "Sengoku" was adopted by Japanese historians in reference...

 and early Edo period

Edo period

The , or , is a division of Japanese history which was ruled by the shoguns of the Tokugawa family, running from 1603 to 1868. The political entity of this period was the Tokugawa shogunate....

.

Life

Mogami Yoshiaki was the first son of Mogami Yoshimori (最上 義守), and succeeded his father as daimyō of Yamagata. When Toyotomi Hideyoshi

Toyotomi Hideyoshi

was a daimyo warrior, general and politician of the Sengoku period. He unified the political factions of Japan. He succeeded his former liege lord, Oda Nobunaga, and brought an end to the Sengoku period. The period of his rule is often called the Momoyama period, named after Hideyoshi's castle...

 came to power, Mogami submitted to his rule, but later became a supporter of Tokugawa Ieyasu

Tokugawa Ieyasu

 was the founder and first shogun of the Tokugawa shogunate of Japan , which ruled from the Battle of Sekigahara  in 1600 until the Meiji Restoration in 1868. Ieyasu seized power in 1600, received appointment as shogun in 1603, abdicated from office in 1605, but...

 following Hideyoshi's death.

In 1600, he battled Uesugi Kagekatsu

Uesugi Kagekatsu

was a daimyo during the Sengoku and Edo periods of Japanese history. The son of Nagao Masakage and husband of Uesugi Kenshin's elder sister, Aya-Gozen. After his father died, he was adopted by Kenshin....

, an enemy of Tokugawa's, alongside Date Masamune

Date Masamune

was a regional strongman of Japan's Azuchi-Momoyama period through early Edo period. Heir to a long line of powerful daimyo in the Tōhoku region, he went on to found the modern-day city of Sendai...

 (his nephew), another lord of the far north

Tohoku region

The is a geographical area of Japan. The region occupies the northeastern portion of Honshu, the largest island of Japan. The region consists of six prefectures : Akita, Aomori, Fukushima, Iwate, Miyagi and Yamagata....

. He aided in Date's siege of Shiroishi

Siege of Shiroishi

The siege of Shiroishi, in 1600, was one of several feudal Japanese battles leading up to the decisive battle of Sekigahara which ended the period of over 100 years of war, and was immediately followed by the establishment of the Tokugawa shogunate...

, and was then attacked in his own home castle of Hataya

Siege of Hataya

The siege of Hataya was one of several battles in Japan's Tōhoku region which served as preludes to the decisive Sekigahara Campaign which would end the 250-year period of war known as Sengoku....

. Later that year, Mogami and Date supported Ieyasu at the famous battle of Sekigahara

Battle of Sekigahara

The , popularly known as the , was a decisive battle on October 21, 1600 which cleared the path to the Shogunate for Tokugawa Ieyasu...

, after which Mogami's domain was expanded to 520,000 koku

Koku

The is a Japanese unit of volume, equal to ten cubic shaku. In this definition, 3.5937 koku equal one cubic metre, i.e. 1 koku is approximately 278.3 litres. The koku was originally defined as a quantity of rice, historically defined as enough rice to feed one person for one year...

in return for his loyal service. 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. Yamagata maintains the Mogami Yoshiaki Historical Museum

Mogami Yoshiaki Historical Museum

The is a museum in Yamagata in Japan just outside the reconstructed Great Eastern Gate of Yamagata Castle. It focuses on the place in history of Mogami Yoshiaki and his role in building the foundations of present-day Yamagata. The Historical Museum opened on 1 December 1989 in commemoration of the...

, just outside the rebuilt Great Eastern Gate of Yamagata Castle, which displays his helmet, battle command baton and other implements he actually used.

Legacy

Mogami Yoshiaki laid out and built the castle town, which became the foundation of modern-day Yamagata City

Yamagata City

* Yamagata , the capital city of Yamagata Prefecture* Yamagata , a city in Gifu Prefecture...

. He controlled the "Three Difficult Places" on the Mogami River

Mogami River

The is a river in Yamagata Prefecture, Japan. It is 224 km long and has a watershed of 7,040 km². It is regarded as one of the three most rapid rivers of Japan ....

, making navigation safer from the Sea of Japan

Sea of Japan

The Sea of Japan is a marginal sea of the western Pacific Ocean, between the Asian mainland, the Japanese archipelago and Sakhalin. It is bordered by Japan, North Korea, Russia and South Korea. Like the Mediterranean Sea, it has almost no tides due to its nearly complete enclosure from the Pacific...

 to the inland, and bringing the culture of Kyōto

Kyoto

is a city in the central part of the island of Honshū, Japan. It has a population close to 1.5 million. Formerly the imperial capital of Japan, it is now the capital of Kyoto Prefecture, as well as a major part of the Osaka-Kobe-Kyoto metropolitan area.-History:...

 and Ōsaka

Osaka

is a city in the Kansai region of Japan's main island of Honshu, a designated city under the Local Autonomy Law, the capital city of Osaka Prefecture and also the biggest part of Keihanshin area, which is represented by three major cities of Japan, Kyoto, Osaka and Kobe...

 to Yamagata. His dam building projects at Kitadaseki, Inabazeki and other places, and other irrigation control measures helped develop rice cultivation in the Shonai plain.

In popular culture

Mogami Yoshiaki appears in the video game Sengoku Basara 3 as a non-playable general supporting Date Masamune's forces during Sekigahara. Here, he is portrayed as an arrogant, deceitful dandy with a look not unlike Snidely Whiplash

Snidely Whiplash

Snidely Whiplash is the cartoon arch-villain to Dudley Do-Right in the tongue-in-cheek Dudley Do-Right of the Mounties segments of The Rocky and Bullwinkle Show by American animation pioneer Jay Ward....

.

Sources

• Stephen Turnbull
  Stephen Turnbull
  Stephen Turnbull may refer to:*Stephen Turnbull *Stephen Turnbull , English footballer...
  
  . The Samurai Sourcebook. London: Cassell & Co. (1998)
• Dewa no Taishu Mogami Yoshiaki