was the 8th and final 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 Mutsuura Domain

Mutsuura Domain

' was a Japanese feudal domain of the Edo period, located in southern Musashi Province in what is now part of Kanagawa Prefecture. Mutsuura was a Fudai domain. It consisted of two separate geographic areas, one in Kuragi District, Musashi, and the other in Osumi District, Sagami, with its...

 in southern Musashi Province

Musashi Province

was a province of Japan, which today comprises Tokyo Prefecture, most of Saitama Prefecture and part of Kanagawa Prefecture. It was sometimes called . The province encompassed Kawasaki and Yokohama...

, Honshū

Honshu

is the largest island of Japan. The nation's main island, it is south of Hokkaido across the Tsugaru Strait, north of Shikoku across the Inland Sea, and northeast of Kyushu across the Kanmon Strait...

, 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...

 (modern-day Kanagawa Prefecture

Kanagawa Prefecture

is a prefecture located in the southern Kantō region of Japan. The capital is Yokohama. Kanagawa is part of the Greater Tokyo Area.-History:The prefecture has some archaeological sites going back to the Jōmon period...

) during the Bakumatsu period.

Biography

Yonekoto Masakoto was the 6th son of the 7th daimyō of Mutsuura Domain, Yonekura Masanaga

Yonekura Masanaga

was the 7th daimyō of Mutsuura Domain in southern Musashi Province, Honshū, Japan and 10th head of the Yonekura clan. His courtesy title was Tango-no-kami.-Biography:...

. In May, 1868, he was presented before Shogun

Shogun

A was one of the hereditary military dictators of Japan from 1192 to 1867. In this period, the shoguns, or their shikken regents , were the de facto rulers of Japan though they were nominally appointed by the emperor...

 Tokugawa Iesada

Tokugawa Iesada

Tokugawa Iesada Tokugawa Iesada Tokugawa Iesada (徳川 家定 (May 6, 1824 – August 14, 1858) was the 13th shogun of the Tokugawa shogunate of Japan who held office for only 5 years, from 1853 to 1858. He was physically weak and therefore unfit to be shogun in this period of great challenges...

 in a formal audience and on June 24, 1860 due to his father’s retirement due to illness, became the head of the Yonekura clan

Yonekura clan

The was a cadet branch of the Takeda clan of Kai Province, some members of whom rose to positions of importance within the administration of the Tokugawa shogunate in mid-Edo period Japan....

, and daimyō of Mutsuura Domain. He served in a number of ceremonial posts within 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...

, including guard duty at Osaka Castle

Osaka Castle

is a Japanese castle in Chūō-ku, Osaka, Japan.Originally called Ozakajō, it is one of Japan's most famous castles, and played a major role in the unification of Japan during the sixteenth century of the Azuchi-Momoyama period.-Description:...

, and participated in both the First Chōshū expedition

First Chōshū expedition

The First Chōshū expedition was a punitive military expedition led by the Tokugawa Shogunate against the Chōshū Domain in retaliation for the attack of Chōshū on the Imperial Palace in the Hamaguri rebellion. The First Chōshū expedition was launched on 1 September 1864.The conflict finally led to...

 and the Second Chōshū expedition

Second Chōshū expedition

The Second Chōshū expedition , also called the Summer War, was a punitive expedition led by the Tokugawa Shogunate against the Chōshū Domain. It followed the First Chōshū expedition of 1864....

. In 1867, he was assigned guard duty over the Yokosuka Naval Arsenal

Yokosuka Naval Arsenal

was one of four principal naval shipyards owned and operated by the Imperial Japanese Navy, and was located at Yokosuka city, Kanagawa prefecture on Tokyo Bay, south of Yokohama...

; however in 1868 during the Boshin War

Boshin War

The was a civil war in Japan, fought from 1868 to 1869 between forces of the ruling Tokugawa shogunate and those seeking to return political power to the imperial court....

 of 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...

, he capitulated to the Satchō Alliance

Satcho Alliance

The ', or Satchō Alliance was a military alliance between the feudal domains of Satsuma and Chōshū formed in 1866 to combine their efforts to overthrow the Tokugawa shogunate of Japan....

 forces without a struggle. For this reason, he was confirmed as domain governor of Mutsuura in June 1869. He left public service with the abolition of the han system

Abolition of the han system

The was an act, in 1871, of the new Meiji government of the Empire of Japan to replace the traditional feudal domain system and to introduce centralized government authority . This process marked the culmination of the Meiji Restoration in that all daimyo were required to return their authority...

 in July 1871.

In 1887, he was ennobled with the title of viscount

Viscount

A viscount or viscountess is a member of the European nobility whose comital title ranks usually, as in the British peerage, above a baron, below an earl or a count .-Etymology:...

 (shishaku) under the kazoku

Kazoku

The was the hereditary peerage of the Empire of Japan that existed between 1869 and 1947.-Origins:Following the Meiji Restoration of 1868, the ancient court nobility of Kyoto regained some of its lost status...

peerage system.

Yonekura Masakoto was married to a daughter of Suwa Tadamichi, daimyō of the Suwa Domain

Suwa Domain

The was a Japanese feudal domain of the Edo period located in Shinano Province. Also called Takashima Domain , the domain was ruled from Takashima Castle, which is located in modern-day Suwa, Nagano Prefecture.-Hineno clan:...

 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...

.