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...

 in mid-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....

 Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

, who ruled Yokosuka Domain

Yokosuka Domain

' was a Japanese feudal domain of the Edo period, located in Tōtōmi Province. Yokosuka was a Fudai domain. It was centered at Yokosuka Castle in the Matsuo district of the city of Kakegawa in Shizuoka Prefecture.-History:...

 in Tōtōmi Province

Totomi Province

was a province of Japan in the area of Japan that is today western Shizuoka Prefecture. Tōtōmi bordered on Mikawa, Suruga and Shinano Provinces. Its abbreviated form name was .-History:...

.

Nishio Tadayuki was the second son of the third daimyō of Yokosuka Domain, Nishio Tadamitsu

Nishio Tadamitsu

was a daimyō in mid-Edo period Japan, who ruled Yokosuka Domain in Tōtōmi Province.Tadamitsu was the 2nd son of Kyōgoku Takatoyo, daimyō of Marugame Domain in Sanuki Province. As Nishio Tadanao, had no heirs, he adopted his nephew in 1729. In 1731, Tadamitsu received the courtesy title of Mondo no...

. As his elder brother Tadamasa died in October 1765, Tadayuki was chosen to succeed his father. In 1766 he received court rank and Yamashiro no Kami. In 1782, he succeeded his newly retired father as daimyō of the Yokosuka Domain

Yokosuka Domain

' was a Japanese feudal domain of the Edo period, located in Tōtōmi Province. Yokosuka was a Fudai domain. It was centered at Yokosuka Castle in the Matsuo district of the city of Kakegawa in Shizuoka Prefecture.-History:...

, also receiving his father's courtesy title of Oki no Kami.

Tadayuki entered the administration of the Tokugawa shogunate

Tokugawa shogunate

The Tokugawa shogunate, also known as the and the , was a feudal regime of Japan established by Tokugawa Ieyasu and ruled by the shoguns of the Tokugawa family. This period is known as the Edo period and gets its name from the capital city, Edo, which is now called Tokyo, after the name was...

 in 1784, holding the concurrent offices of Sōshaban

Sōshaban

were officials of the Tokugawa shogunate in Edo period Japan. Conventional interpretations have construed this Japanese title as "master of ceremonies."...

and Jisha-bugyō

Jisha-bugyo

was a "commissioner" or an "overseer" of the Tokugawa shogunate in Edo period Japan. Appointments to this prominent office were always fudai daimyō, the lowest-ranking of the shogunate offices to be so restricted...

. There was a brief period where he was barred from service (after the burning of his Edo

Edo

, also romanized as Yedo or Yeddo, is the former name of the Japanese capital Tokyo, and was the seat of power for the Tokugawa shogunate which ruled Japan from 1603 to 1868...

 residence later that year), but he was soon back to work, and even retained his position despite the fact that his father-in-law was Tanuma Okitsugu

Tanuma Okitsugu

' was a rōjū of the Tokugawa shogunate who introduced monetary reform. He was also a daimyo, and ruled the Sagara han. He used the title Tonomo-no-kami....

. During his tenure, Tadayuki assisted in the attainder

Attainder

In English criminal law, attainder or attinctura is the metaphorical 'stain' or 'corruption of blood' which arises from being condemned for a serious capital crime . It entails losing not only one's property and hereditary titles, but typically also the right to pass them on to one's heirs...

 of Sagara Domain

Sagara Domain

' was a Japanese feudal domain of the Edo period, located in Tōtōmi Province. Yokosuka was a Fudai domain. It was centered in what is now the Sagara district of Makinohara city, Shizuoka Prefecture.-History:...

.

In the administration of Yokosuka Domain, Tadayuki improved the financial situation by encouraging sweet potato

Sweet potato

The sweet potato is a dicotyledonous plant that belongs to the family Convolvulaceae. Its large, starchy, sweet-tasting, tuberous roots are an important root vegetable. The young leaves and shoots are sometimes eaten as greens. Of the approximately 50 genera and more than 1,000 species of...

 cultivation and research into sugar refining. He also had a great personal interest in the arts and in rangaku

Rangaku

Rangaku is a body of knowledge developed by Japan through its contacts with the Dutch enclave of Dejima, which allowed Japan to keep abreast of Western technology and medicine in the period when the country was closed to foreigners, 1641–1853, because of the Tokugawa shogunate’s policy of national...

, and employed many prominent figures in this field, including Takamori Kankō.

Tadayuki died in Yokosuka Castle

Yokosuka Castle

was a Japanese castle in Tōtōmi Province , Japan from the late Muromachi period to the Meiji Restoration. It was the capital of Yokosuka Domain during the Tokugawa shogunate of the Edo period.-History:...

, on May 9, 1801. As his biological son had died young, his adopted heir Nishio Tadayoshi

Nishio Tadayoshi

was a daimyō in mid-Edo period Japan, who ruled Yokosuka Domain in Tōtōmi Province.Nishio Tadayoshi was the fourth son of Makino Sadanaga, daimyō of Kasama Domain in Hitachi Province. He became the adopted heir of the fourth daimyō of Yokosuka Domain, Nishio Tadayuki, in 1783 and married Tadayuki's...

 succeeded him. His grave is located at the Nishio clan temple of Ryumin-ji in modern Kakegawa, Shizuoka

Kakegawa, Shizuoka

is a city in western Shizuoka Prefecture, Japan. As of 2010, the city had an estimated population of 117,858 and a population density of 444 persons per km². The total area was 265.63 km².-Geography:...

.