was a Japanese samurai

Samurai

is the term for the military nobility of pre-industrial Japan. According to translator William Scott Wilson: "In Chinese, the character 侍 was originally a verb meaning to wait upon or accompany a person in the upper ranks of society, and this is also true of the original term in Japanese, saburau...

 of the late 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....

, who served the Makino clan

Makino clan

The are a daimyō branch of the samurai Minamoto clan in Edo period Japan.In the Edo period, the Makino were identified as one of the fudai or insider daimyō clans which were hereditary vassals or allies of the Tokugawa clan, in contrast with the tozama or outsider clans.-Makino clan branches:The...

 of Nagaoka

Nagaoka Domain

The ' was a Japanese domain of the Edo period, located in Echigo Province . It was ruled by the Makino clan for most of its history. It was also the center of some of the fiercest fighting of the Boshin War, during the summer of 1868. Nagaoka joined the Ōuetsu Reppan Dōmei during the war, and...

. Also known by his formal name, . Yamamoto served as a senior commander of Nagaoka forces 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....

. He continued to fight after the fall of Nagaoka, and was killed in action in Aizu

Aizu

is an area comprising the westernmost third of Fukushima Prefecture in Japan. The principal city of the area is Aizuwakamatsu.During the Edo period, Aizu was a feudal domain known as and part of Mutsu Province.-History:...

 in the fall of 1868.

Admiral Yamamoto Isoroku was adopted by Yamamoto's surviving relatives, in order to continue the family line.