Maizuru Naval District

Maizuru Naval District (舞鶴鎮守府, Maizuru chinjufu^?) was one of four main administrative districts of the pre-war Imperial Japanese Navy. Its territory included the entire Sea of Japan coastline from northern Kyūshū to western Hokkaidō.

The strategic importance of the location of Maizuru and its potential for development into a military port for operations in the Sea of Japan towards Korea, Russia and even China was early recognized by the Imperial Japanese Navy. During the administrative re-organization of the Navy in 1889, Maizuru was designated as the headquarters of the Fourth Naval District (第四海軍区, dai-yon kaigunku), and its harbor was dredged, a breakwater constructed and docking facilities for warships were established.

With the First Sino-Japanese War, the port was fortified with the addition of heavy coastal artillery. However, the naval bases at Sasebo and Kure were geographically more convenient for the Navy during the war, and received the bulk of the Navy's attention and funding. Although naval repair facilities and shipyards Maizuru Naval Arsenal were opened in 1903, the mountainous terrain around Maizuru port proved an impediment to expansion, and the area languished as somewhat of a backwater. This continued even through the Russo-Japanese War, despite Maizuru's more convenient location to the center of that conflict. In the post-war period, with Korea in Japanese hands, and the threats from Russia and China very much diminished, there were discussions about closing the military port. Although Maizuru was one of the largest military shipyards in Japan (specializing in destroyer construction), the Washington Naval Treaty of 1923 also considerably reduced the demand for warship construction, and its facilities were largely until 1936.

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