Viscount was a Japanese Navy admiral faithful to the Tokugawa Shogunate, who fought against the new Meiji government until the end of the Boshin War, but later served in the government as one of the founders of the Imperial Japanese Navy.
At the age of 26, Enomoto was sent to the Netherlands to study western techniques in naval warfare and to procure western technologies. He stayed in Europe from 1862 to 1867, and became fluent in both the Dutch and English languages.
Enomoto returned to Japan onboard Kaiyō Maru, a steam warship purchased from the Netherlands by the Shogunal government. During his stay in Europe, Enomoto had realized that the telegraph would be an important means of communication in the future, and started planning a system to connect Edo and Yokohama. Upon his return, Enomoto was promoted to , the second highest rank in the Tokugawa Navy, at the age of 31. He also received the court title of .
During the Meiji restoration, after the surrender of Edo in 1868 during the Boshin War to forces loyal to the new Meiji government, Enomoto refused to deliver up his warships, and escaped to Hakodate in Hokkaidō with the remainder of the Tokugawa Navy and a handful of French military advisers and their leader Jules Brunet. His fleet of eight steam warships was the strongest in Japan at the time.
Enomoto hoped to create an independent country under the rule of the Tokugawa family in Hokkaidō, but the Meiji government refused to accept partition of Japan. On 25 December, the Tokugawa loyalists declared the foundation of the Republic of Ezo and elected Enomoto as president.
The next year, the Meiji government forces invaded Hokkaidō and defeated Enomoto's forces in the Naval Battle of Hakodate. On 18 May 1869 the Republic of Ezo collapsed, and Hokkaidō came under the rule of the central government headed by the Meiji Emperor.
In 1874, Enomoto was given the rank of vice-admiral in the fledgling Imperial Japanese Navy. The following year, he was sent as a special envoy, he was sent to Russia to negotiate the Treaty of Saint Petersburg (1875). The successful conclusion of the treaty was very well received in Japan and further raised Enomoto's prestige within the ruling circles, and the fact that Enomoto had been chosen for such an important mission was seen as evidence of reconciliation between former foes in the government.
In 1880, Enomoto became . In 1885 his diplomatic skills were again called upon to assisting Ito Hirobumi in concluding the Convention of Tientsin with Qing China. Afterwards, Enomoto held a series of high posts with in the Japanese government. He was Japan's first Minister of Communications (1885-1888) after the introduction of the cabinet system in 1885. He was also Minister of Agriculture and Commerce in 1888 and again from 1894 to 1897, Minister of Education from 1889-1890 and Foreign Minister from 1891-1892.
Enomoto was especially active in promoting Japanese emigration through settler colonies in the Pacific Ocean and South and Central America. In 1891 he established - against the will of the cabinet of Matsukata Masayoshi - a 'section for emigration' in the Foreign Ministry, with the task of encouraging emigration and finding new potential territories for Japanese settlement overseas. Two years later, after leaving the government, Enomoto also helped to establish a private organization, the 'Colonial Association', to promote external trade and emigration.
Enomoto died in 1908 at the age of 72. His grave is at the temple of Kichijo-ji in Tokyo.