The was a short-lived Japanese domain

Han (Japan)

The or domain was the name of the estate belonging to a warrior in Japan after the 17th century. The fiefs of the daimyos of the samurai class of Japan during the Edo period were called han.-Edo period:...

 of the 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....

, located in Shinano Province

Shinano Province

or is an old province of Japan that is now present day Nagano Prefecture.Shinano bordered on Echigo, Etchū, Hida, Kai, Kōzuke, Mikawa, Mino, Musashi, Suruga, and Tōtōmi Provinces...

 (present-day Nagano prefecture

Nagano Prefecture

is a prefecture of Japan located in the Chūbu region of the island of Honshū. The capital is the city of Nagano.- History :Nagano was formerly known as the province of Shinano...

). The sole lord of Ōhama was Mizuno Tadatomo. Tadatomo, who had previously been a high-income hatamoto

Hatamoto

A was a samurai in the direct service of the Tokugawa shogunate of feudal Japan. While all three of the shogunates in Japanese history had official retainers, in the two preceding ones, they were referred to as gokenin. However, in the Edo period, hatamoto were the upper vassals of the Tokugawa...

 with holdings in the Saku district

Saku District, Nagano

was a district located in Shinano Province or Nagano Prefecture.The former is estimated to be located at Nagatoro in the city of Saku....

 of Shinano Province

Shinano Province

or is an old province of Japan that is now present day Nagano Prefecture.Shinano bordered on Echigo, Etchū, Hida, Kai, Kōzuke, Mikawa, Mino, Musashi, Suruga, and Tōtōmi Provinces...

, served as a page and later an assistant to the 10th shogun, Ienari

Tokugawa Ienari

Tokugawa Ienari; 徳川 家斉 was the eleventh and longest serving shogun of the Tokugawa shogunate of Japan who held office from 1787 to 1837.-First wife:...

. When he was promoted to wakadoshiyori

Wakadoshiyori

The ', or "Junior Elders", were high government officials in 17th century Tokugawa Japan. The position was established around 1631, but appointments were irregular until 1662....

, 5000 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...

 was added to his income, making him a fudai

Fudai

was a class of daimyo who were hereditary vassals of the Tokugawa in Edo period Japan. It was primarily the fudai who filled the ranks of the Tokugawa administration.-Origins:...

 daimyo, and his landholdings into a formal han

Han (Japan)

The or domain was the name of the estate belonging to a warrior in Japan after the 17th century. The fiefs of the daimyos of the samurai class of Japan during the Edo period were called han.-Edo period:...

 of over 10,000 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...

.

Tadatomo's family was later transferred to the Numazu Domain

Numazu Domain

' was a Japanese feudal domain of the Edo period, located in Suruga Province. Numazu was a Fudai domain. It was centered on what is now the city of Numazu, Shizuoka.-History:...

, where it remained until the Meiji Restoration

Meiji Restoration

The , also known as the Meiji Ishin, Revolution, Reform or Renewal, was a chain of events that restored imperial rule to Japan in 1868...

.