Shinjō Domain

The Mogami established a subsidiary holding centered on Sakanobe Castle in what is now Mamurogawa in Yamagata, based on the Sengoku-period foundations of a structure erected by the Onodera clan.

Tozawa Moriyasu, a relatively minor daimyō originally from Kakunodate in Dewa Province served Toyotomi Hideyoshi at the Battle of Odawara in 1590; however, he fell ill and died shortly thereafter.

His son, Tozawa Masamori sided with Tokugawa Ieyasu at the Battle of Sekigahara, and was eventually promoted to the status of a 40,000-koku daimyō at Hitachi-Matsuoka Domain in Hitachi Province.

When the Mogami were dispossessed, the Tokugawa shogunate transferred him from Hitachi to the newly created Shinjō Domain, and increased his revenues to 60,000 koku, where his descendants ruled for 11 generations to the Meiji Restoration.

The 11th daimyō, Tozawa Masazane escaped to Kubota Castle, where he remained in exile for 70 days until his domain was liberated by forces loyal to the new Meiji government.