Shōnai Domain (庄内藩,Shōnai-han) was afeudal domain inEdo period Japan, located inDewa Province (modern-dayYamagata Prefecture),Japan. It was centered onTsuruoka Castle in what is now the city ofTsuruoka inYamagata Prefecture, and was thus also known as theTsuruoka Domain (鶴岡藩,Tsuruoka han). It was governed for the whole of its history by theSakai clan, which resulted in an unusually stable and prosperous domain. During their rule over Shōnai, the Sakai clan was ranked as a province-holdingdaimyō (国持ち大名,kunimochi daimyō) family, and as such, had the privilege ofshogunal audiences in the Great Hall (Ohiroma) ofEdo Castle.^[1] In theBoshin War of 1868–69, the domain joined theŌuetsu Reppan Dōmei, the alliance of northern domains supporting theTokugawa shogunate, but then later defected to the imperial side. As with all other domains, it wasdisbanded in 1871.

Shōnai Domain 庄内藩
under Tokugawa shogunate Japan
1622–1871
Flag
Capital	Tsurugaoka Castle
Area
• Coordinates	38°43′43.46″N139°49′28.39″E / 38.7287389°N 139.8245528°E /38.7287389; 139.8245528
• Type	Daimyō
Historical era	Edo period
• Established	1622
• Disestablished	1871
Today part of	part ofYamagata Prefecture

The Sakai rose to prominence withSakai Tadatsugu, who was one ofTokugawa Ieyasu'sShitennō, or four leading generals and thedaimyō ofMatsushiro Domain inShinano Province. After the death ofMogami Yoshiaki many internal struggles for control of theMogami clan, the former rulers of Dewa Province, arouse and caused their vast domain to be divided into several parts. Sakai Tadatsugu was awarded the coastal region consisting of Tagawa, Akumi and Murayama districts, which increased hiskokudaka from 38,000koku to 138,000koku, and then to 150,000koku. However, the lands of the Shōnai region were fertile and well-watered, and eminently suited for growing rice, which gave the Sakai clan actual revenues of more than 200,000koku. This revenue was further supplemented by the developed of Sakata port for the coastalkitamaebune trade, which gave the clan an actual income of closer to 300,000koku.

In 1805, thedomain academy, theChidōkan was established by the 7thdaimyō, Sakai Tadaari.The domain faced a severe crisis during the time of the 9thdaimyō, Sakai Tadakata, when it came to the attention ofshōgunTokugawa Ienari that the domain's revenues had been understated by some 200,000koku for many decades. Ienari decided to relocate the Sakai clan toNagaoka Domain (74,000koku) and to move the Makino clan from Nagaoka toKawagoe Domain (150,000koku). Matsudaira Narisasa of in Kawagoe (who happened to be Ienari's son) would then be given Shōnai. The proposal sparked tremendous outrage in Shōnai domain, and a large number of commoners, merchants, samurai and officials descended upon Edo in 1840 to file protests and petitions in what came to be known as the Tenpo Gimin Jiken (天保義民事件). The move was cancelled by the timely deaths of both Ienari and his son Matsudaira Narisada within weeks of each other in 1841 and Shōnai was "punished" by being assigned various public works projects.

During theBakumatsu period, Shōnai was assigned the task of building fortifications and providing increased security for Edo from the incursions of foreign ships, and had its official income increased to 167,000koku in 1864. In January 1868, samurai from Shōnai domain joined withKaminoyama Domain in an attack on theSatsuma Domain residence in Edo – which marks the start of theBoshin War. Shōnai was initially a strong supporter of theŌuetsu Reppan Dōmei, an alliance of northern domains against the forces of the western-basedSatsuma-Chōshu Alliance attempting to overthrow the Tokugawa shogunate. However, Shōnai (along with the other military leader in the region,Aizu Domain) did not sign initially sign the treaty forming the Alliance and only became an official member in early 1868. Shōnai was regarded with caution by the Satchō Alliance, as it had deep financial resources, and had rearmed with modern weapons supplied by theSchnell brothers. However, after the defection ofKubota Domain to the imperial side, and the defeat of the Northern Alliance at theBattle of Hokuetsu and theBattle of Aizu, Shōnai Domain surrendered without a fight in December. Sakai Tadazumi turned the domain over to his son, Sakai Tadamichi and the domain was reduced to 120,000koku. However, in June 1869, the Sakai were ordered to relocate toIwakitaira Domain. This move was strongly protested by the people of the domain, who raised 300,000ryō as payment to the Meiji government, and obtained the support ofSaigō Takamori to have the order rescinded. In 1870, the domain name was changed toOizumi Domain (大泉藩,Oizumi-han). The domain was abolished together with all of the domains in theabolition of the han system in 1871, becoming Sakata Prefecture and Tsuruoka Prefecture, which then merged into Yamagata Prefecture. The Sakai clan was ennobled in 1885, becominghakushaku (counts) in thekazoku peerage.

•  Sakai clan (fudai) 1622–1871

^[2]

• Dewa Province (Uzen)
  • 399 villages in Tagawa District
  • 249 villages in Akumi District
• Ezo (Ishikari)
  • 1 trading post in Hamamasu District
• Ezo (Teshio)
  • 1 trading post in Teshio District
  • 1 trading post in Nakagawa District
  • 1 trading post in Kawakami District
  • 1 trading post in Rumoi District
  • 1 trading post in Tomamae District

Dewa Matsuyama Domain (出羽松山藩,Dewa Matsuyama han) was founded in 1647 for Sakai Tadatsune, the third son of Sakai Tadakatsu, who was assigned 20,000koku of new rice lands in Akumi District. The thirddaimyō, Sakai Tadayoshi served aswakadoshiyori, and was awarded an additional 5000koku inKōzuke Province. He also built the Dewa-Matsuyama Castle, from which his successors continued to rule until theMeiji Restoration. During theBoshin War, the domain sided with the Ōuetsu Reppan Dōmei, for which it was punished by the Meiji government with the loss of 2500koku. It was renamed Matsumine Domain (松嶺藩,Matsumine han) in 1869, and was abolished with all the other domains in 1871. The finaldaimyō, Sakai Tadamasa subsequently received thekazoku peerage title ofshishaku (viscount).

•  Sakai clan (fudai) 1647–1871

• Dewa Province (Uzen)
  • 62 villages in Murayama District
  • 10 villages in Tagawa District
  • 44 villages in Akumi District
• Kōzuke Province
  • 6 villages in Seta District

Ōyama Domain (大山藩,Ōyama-han) was founded in 1647 for Sakai Tadatoki, the seventh son of Sakai Tadakatsu, who was assigned 10,000koku of new rice lands in Tagawa District. It reverted to the parent domain on his death in 1668 without an heir.

• Onodera, Eikō (2005).Boshin nanboku sensō to Tōhoku seiken. Sendai: Kita no mori.
• Papinot, E. (1910).Historical and Geographic Dictionary of Japan. Tuttle (reprint) 1972.

• (in Japanese)"Tsuruoka-han" on Edo 300 HTML (accessed 15 August 2008)