was the first of four main administrative districts of the pre-war

Imperial Japanese Navy The Imperial Japanese Navy (IJN; Kyūjitai: Shinjitai: ' 'Navy of the Greater Japanese Empire', or ''Nippon Kaigun'', 'Japanese Navy') was the navy of the Empire of Japan from 1868 to 1945, when it was dissolved following Japan's surrender ...

. Its territory included

Tokyo Bay is a bay located in the southern Kantō region of Japan, and spans the coasts of Tokyo, Kanagawa Prefecture, and Chiba Prefecture. Tokyo Bay is connected to the Pacific Ocean by the Uraga Channel. The Tokyo Bay region is both the most populous a ...

and the

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

coasts of central and northern

Honshū , historically called , is the largest and most populous island of Japan. It is located south of Hokkaidō across the Tsugaru Strait, north of Shikoku across the Inland Sea, and northeast of Kyūshū across the Kanmon Straits. The island separa ...

from the

Kii Peninsula The is the largest peninsula on the island of Honshū in Japan. It is named after the ancient Kii Province. Overview The area south of the “ Central Tectonic Line” is called , and is home to reef-like coral communities which are amongst ...

to Shimokita Peninsula. Its headquarters, along with most of its installations, including the

Yokosuka Naval Arsenal was one of four principal naval shipyards owned and operated by the Imperial Japanese Navy, and was located at Yokosuka, Kanagawa prefecture on Tokyo Bay, south of Yokohama. History In 1866, the Tokugawa shogunate government established the ...

, were located in the city of

Yokosuka is a city in Kanagawa Prefecture, Japan. , the city has a population of 409,478, and a population density of . The total area is . Yokosuka is the 11th most populous city in the Greater Tokyo Area, and the 12th in the Kantō region. The city ...

, which constituted the Yokosuka Naval Base.

History

The location of

at the entrance to strategic

was recognized of critical importance by the

Tokugawa shogunate The Tokugawa shogunate (, Japanese 徳川幕府 ''Tokugawa bakufu''), also known as the , was the military government of Japan during the Edo period from 1603 to 1868. Nussbaum, Louis-Frédéric. (2005)"''Tokugawa-jidai''"in ''Japan Encyclopedia ...

and early

Meiji government The was the government that was formed by politicians of the Satsuma Domain and Chōshū Domain in the 1860s. The Meiji government was the early government of the Empire of Japan. Politicians of the Meiji government were known as the Meiji o ...

. In 1866, the

government established the ''Yokosuka Seisakusho'', a military

arsenal An arsenal is a place where arms and ammunition are made, maintained and repaired, stored, or issued, in any combination, whether privately or publicly owned. Arsenal and armoury (British English) or armory (American English) are mostly ...

and

naval base A naval base, navy base, or military port is a military base, where warships and naval ships are docked when they have no mission at sea or need to restock. Ships may also undergo repairs. Some naval bases are temporary homes to aircraft that us ...

, with the help of foreign engineers, including the French

naval architect This is the top category for all articles related to architecture and its practitioners. {{Commons category, Architecture occupations Design occupations Architecture, Occupations ...

Léonce Verny François Léonce Verny, (2 December 1837 – 2 May 1908) was a French officer and naval engineerSims, Richard. (1998) ''French Policy Towards the Bakufu and Meiji Japan 1854-95: A Case of Misjudgement and Missed Opportunities,'' p. 246./ref> ...

. The new facility was intended to produce modern, western-style

warship A warship or combatant ship is a naval ship that is built and primarily intended for naval warfare. Usually they belong to the armed forces of a state. As well as being armed, warships are designed to withstand damage and are usually faster a ...

s and equipment for the Tokugawa navy. After the

Boshin War The , sometimes known as the Japanese Revolution or Japanese Civil War, was a civil war in Japan fought from 1868 to 1869 between forces of the ruling Tokugawa shogunate and a clique seeking to seize political power in the name of the Imperi ...

and the

Meiji Restoration The , referred to at the time as the , and also known as the Meiji Renovation, Revolution, Regeneration, Reform, or Renewal, was a political event that restored practical imperial rule to Japan in 1868 under Emperor Meiji. Although there were ...

, the new Meiji government took over control of the facility in 1871, renaming it the ''Yokosuka Zosenjo'' (Yokosuka Shipyards). In August 1876, the Imperial Japanese Navy was organized into eastern and a western strategic zones, with the eastern zone based at Yokosuka, and the western zone based at

Nagasaki is the capital and the largest city of Nagasaki Prefecture on the island of Kyushu in Japan. It became the sole port used for trade with the Portuguese and Dutch during the 16th through 19th centuries. The Hidden Christian Sites in the ...

. However, for ease of communications with naval headquarters in

Tokyo Tokyo (; ja, 東京, , ), officially the Tokyo Metropolis ( ja, 東京都, label=none, ), is the capital and largest city of Japan. Formerly known as Edo, its metropolitan area () is the most populous in the world, with an estimated 37.468 ...

, the Tōkai Naval District was relocated to

Yokohama is the second-largest city in Japan by population and the most populous municipality of Japan. It is the capital city and the most populous city in Kanagawa Prefecture, with a 2020 population of 3.8 million. It lies on Tokyo Bay, south of To ...

in September 1876. With the reorganization of the Imperial Japanese Navy in April 1886, Japan was divided into five naval districts for recruiting and supply, and the headquarters for the Tokai Naval District was relocated back to Yokosuka, becoming the Yokosuka Naval District, and the

was placed under its command. As with all naval districts, it was under the direction of the Navy Ministry during peacetime, and came under the command of the fleets stationed within the district in time of war. A Bureau of Torpedo Warfare was established at Yokusuka in June 1885. In a further administrative re-organization of the Japanese Navy in 1889, Yokosuka was designated as the , and its harbor was dredged, a

breakwater Breakwater may refer to: * Breakwater (structure), a structure for protecting a beach or harbour Places * Breakwater, Victoria, a suburb of Geelong, Victoria, Australia * Breakwater Island Breakwater Island () is a small island in the Palme ...

extended and docking facilities for

s were increased. A Bureau of Mine Warfare was also established. In 1893, schools for naval mechanical engineering, torpedo warfare and

naval artillery Naval artillery is artillery mounted on a warship, originally used only for naval warfare and then subsequently used for naval gunfire support, shore bombardment and anti-aircraft roles. The term generally refers to tube-launched projectile-firi ...

were established. Schools for naval engineering, and for mine warfare followed in 1907 and a naval medical center in 1908.

Naval aviation Naval aviation is the application of military air power by navies, whether from warships that embark aircraft, or land bases. Naval aviation is typically projected to a position nearer the target by way of an aircraft carrier. Carrier-based a ...

facilities were established in June 1912, followed by a

wireless communications Wireless communication (or just wireless, when the context allows) is the transfer of information between two or more points without the use of an electrical conductor, optical fiber or other continuous guided medium for the transfer. The most ...

facility in April 1913. On January 14, 1917, the

armoured cruiser The armored cruiser was a type of warship of the late 19th and early 20th centuries. It was designed like other types of cruisers to operate as a long-range, independent warship, capable of defeating any ship apart from a battleship and fast eno ...

Tsukuba is a city located in Ibaraki Prefecture, Japan. , the city had an estimated population of 244,528 in 108,669 households and a population density of 862 persons per km². The percentage of the population aged over 65 was 20.3%. The total ar ...

'' exploded and sank in Yokosuka port in an accident. The Naval Construction Department was established in 1921. In June 1930, a Naval Communications School was established, but the Naval Mine School was made independent of the naval district. A Naval Aviation School was established in April 1934.

Pacific war

At the time of the

attack on Pearl Harbor The attack on Pearl HarborAlso known as the Battle of Pearl Harbor was a surprise military strike by the Imperial Japanese Navy Air Service upon the United States against the naval base at Pearl Harbor in Honolulu, Territory of Hawaii, j ...

in 1941, Yokosuka Naval District encompassed the following * Yokosuka Naval District HQ ** Yokosuka Naval Base *** Yokosuka Naval Base HQ *** Yokosuka Communications Center *** Yokosuka Supply Department *** Accounting Department *** Construction Department *** Ports & Docks Unit ***

*** Naval Hospital *** Naval Prison *** Naval Fuel Depot *** Yokosuka Base Garrison *** Yokosuka 1st Naval BarracksSenshi Sōsho (1975), appendix table "Order of battle of the Combined Fleet on 10 December 1941". *** Yokosuka 2nd Naval Barracks *** Yokosuka Special Naval Landing Forces ** Yokosuka Submarine Base ** Yokosuka Security Squadron *** Auxiliary Cruiser ''Noshiro Maru'', Auxiliary gunboat ''Shoei Maru'', ''Meiji Maru No. 1'' *** Yokosuka Local Defence Squadron *** Minesweeper Division 25; Auxiliary minesweeper ''Misago Maru No. 1'', ''Misago Maru No. 3'', ''Kongo Maru No. 2'', ''Naruo Maru'', ''Shintohoku Maru'', ''Togo Maru'' *** Minesweeper Division 26; Auxiliary minesweeper ''Banshu Maru No. 18'', ''Keijin Maru No. 1'', ''Keijin Maru No. 2'', ''Showa Maru No. 10'', ** Submarine tender ''Komahashi'' ** Destroyer , ** Submarine Chaser ''No. 22'', ''No. 23'' **

Yokosuka Naval Air Group The was the first aviation unit established by the Imperial Japanese Navy in 1916 and survived until the end of the Pacific War. It was charged with educating and training aviation personnel, practical testing of new aircraft, and tactical rese ...

(Oppama) ** Tateyama Naval Air Group ** Kisarazu Naval Air Group ** 11th Combined Air Group (Training) *** Kasumigaura Naval Air Group *** Tsukuba Naval Air Group *** Yatabe Naval Air Group *** Hyakurihara Naval Air Group (Ibaraki Pref) *** Kashima Naval Air Group *** Suzuka Naval Air Group *** Tsuchiura Naval Air Group In May 1945,

Michitaro Tozuka was a vice admiral in the Imperial Japanese Navy in World War II. Biography Tozuka was a native of the former Sendagaya Village in Tokyo, now part of Shibuya. He graduated 33rd out of 149 cadets in the 38th class of the Imperial Japanese Naval ...

became the final commander of the Yokosuka Naval District. Yokosuka was bombed by

United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...

and

United States Army Air Forces The United States Army Air Forces (USAAF or AAF) was the major land-based aerial warfare service component of the United States Army and ''de facto'' aerial warfare service branch of the United States during and immediately after World War II ...

aircraft in the final stages of the

Pacific War The Pacific War, sometimes called the Asia–Pacific War, was the theater of World War II that was fought in Asia, the Pacific Ocean, the Indian Ocean, and Oceania. It was geographically the largest theater of the war, including the vast ...

, most notably during the

attack on Yokosuka The attack on Yokosuka was an air raid conducted by the United States Navy on 18 July 1945 during the last weeks of the Pacific War. The was the raid's main target, though anti-aircraft positions and other warships at Yokosuka Naval Arsena ...

on 18 July 1945, but many of its facilities were captured intact by the Allied forces. The Yokosuka area came under occupation by American forces during the

occupation of Japan Japan was occupied and administered by the victorious Allies of World War II from the 1945 surrender of the Empire of Japan at the end of the war until the Treaty of San Francisco took effect in 1952. The occupation, led by the United States wi ...

, and most of the facilities of the former Yokosuka Naval District were inherited by the

United States 7th Fleet The Seventh Fleet is a numbered fleet of the United States Navy. It is headquartered at U.S. Fleet Activities Yokosuka, in Yokosuka, Kanagawa Prefecture, Japan. It is part of the United States Pacific Fleet. At present, it is the largest of t ...

and are now known as

United States Fleet Activities Yokosuka or is a United States Navy base in Yokosuka, Japan. Its mission is to maintain and operate base facilities for the logistic, recreational, administrative support and service of the U.S. Naval Forces Japan, Seventh Fleet and other operating f ...

. A small portion of the area continues to be used by the modern post-war

Japanese Maritime Self-Defense Force , abbreviated , also simply known as the Japanese Navy, is the maritime warfare branch of the Japan Self-Defense Forces, tasked with the naval defense of Japan. The JMSDF was formed following the dissolution of the Imperial Japanese Navy (IJN) ...

and are now known as

JMSDF Yokosuka Naval Base , also simply known as the JMSDF Yokosuka Naval Base, is a group of ports and land facilities of the Japan Maritime Self-Defense Force (JMSDF), which are scattered in multiple districts of Yokosuka City, Kanagawa Prefecture, and where the Yokos ...

, which has preserved a portion of the original red brick gates.

List of commanders

Commander of Tōkai Naval District

Director of Yokusuka Naval District

Commanding officers of Yokusuka Naval District

References

;Notes ;Bibliography * * * ''

Senshi Sōsho The , also called the , is the official military history of Imperial Japan's involvement in the Pacific War from 1937 to 1945. The task of compiling the official account of the Japanese involvement in World War II began in October 1955 with the op ...

'' Vol. 80, ''Combined Fleet #2, "Until June 1942"'', Asagumo Simbun (Tokyo, Japan), 1975. {{Authority control Imperial Japanese Navy