, also known as ''kaigun-bugō,'' were officials of the

Tokugawa shogunate The Tokugawa shogunate (, Japanese 徳川幕府 ''Tokugawa bakufu''), also known as the , was the military government of Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in ...

Edo period The or is the period between 1603 and 1867 in the history of Japan, when Japan was under the rule of the Tokugawa shogunate and the country's 300 regional ''daimyo''. Emerging from the chaos of the Sengoku period, the Edo period was character ...

Japan. Appointments to this prominent office were usually '' fudai daimyō''.Beasley, William G. (1955). ''Select Documents on Japanese Foreign Policy, 1853–1868'', p. 322. Conventional interpretations have construed these Japanese titles as "commissioner", "overseer" or "governor". This ''

bakufu , officially , was the title of the military dictators of Japan during most of the period spanning from 1185 to 1868. Nominally appointed by the Emperor, shoguns were usually the de facto rulers of the country, though during part of the Kamakura ...

'' title identifies an official with responsibility for naval matters. The office was created on March 28, 1859. The creation of this new position was an administrative change which was deemed necessary because of two treaties which were negotiated with the Americans. The open port provisions were part of the

Convention of Kanagawa The Convention of Kanagawa, also known as the Kanagawa Treaty (, ''Kanagawa Jōyaku'') or the Japan–US Treaty of Peace and Amity (, ''Nichibei Washin Jōyaku''), was a treaty signed between the United States and the Tokugawa Shogunate on March ...

of 1858, which cam about as the result Commodore Perry's second appearance in Tokyo harbor with armed battleships. More precisely, this ''bugyō'' was considered essential because of the Treaty of Amity and Commerce, which had been negotiated in 1858 by the American representative, Townsend Harris—the Harris Treaty of 1858). The ''gunkan-bugyō'' was considered to rank approximately with the '' kanjō-bugyō''. The genesis of the ''gunkan-bugyō'' pre-dates the actual creation of the office.

''Kaibō-gakari''

The prefix ''kaibō-gakari'' meaning "in charge of maritime defense" was used with the titles of some ''bakufu'' officials after 1845. This term was used to designate those who bore a special responsibility for overseeing coastal wat