Sasebo Naval District (Sasebo Chinjufu)

In 1886 the Japanese government issued regulations dividing the coast into naval districts, each under a chinjufu, and selected Sasebo and Kure as naval ports. Sasebo, at the north-western tip of Kyushu, has a deep harbour with a narrow entrance and faces Korea and China. The Sasebo Naval District (佐世保鎮守府, Sasebo Chinjufu) was established on July 1, 1889, as one of four principal naval districts protecting the Japanese home islands, alongside Yokosuka, Kure, and Maizuru; its first commander was Akamatsu Noriyoshi. Located in Sasebo, Nagasaki Prefecture, it was responsible for the defense of western Japan and the naval jurisdiction over the Third Naval District — Kyushu and Okinawa, with (in this site's earlier text) Shikoku, twelve prefectures in total — and, as the empire expanded, waters towards Korea and Taiwan.

The district headquarters controlled the whole naval port: the Sasebo Naval Arsenal (established 1903), the naval barracks that trained recruits, a naval hospital, supply and fuel departments, defence units and, from 1920, the Sasebo Naval Air Group. In the Sino-Japanese and Russo-Japanese Wars Sasebo was the Combined Fleet's sortie and repair base; the battleship Mikasa sank in Sasebo harbour after a magazine explosion in September 1905. During World War I, warships attached to the Sasebo Naval District formed the core of the Second Special Squadron that served with distinction in the Mediterranean, escorting Allied convoys. The Hario radio towers, completed in 1922, were a key long-range naval communications facility.

During World War II, Sasebo served as a major naval base for operations in the Pacific, supplying and repairing ships for the East China Sea, the Nansei Islands and the southern front. The arsenal concentrated on repair and conversion; its No. 7 dock, completed in 1941, could take Yamato-class battleships, and the battleship Musashi was docked there. Associated facilities included the torpedo works and suicide-boat training station at Kawatana and the naval air arsenal at Ōmura. On the night of June 28–29, 1945, B-29s firebombed Sasebo, killing more than 1,200 people and burning the district headquarters.

The naval district was abolished on November 30, 1945. After the war, the base was occupied by U.S. forces and continues today as Commander Fleet Activities Sasebo (CFAS), a U.S. Navy installation and a key logistics base during the Korean War; in 1953 the forerunner of the JMSDF established its Sasebo District Force there, creating the shared port of today. The red-brick warehouses, docks, cranes and radio towers left by the Imperial Navy were recognised in 2016, together with Yokosuka, Kure and Maizuru, as the Japan Heritage "Chinjufu" naval-port story.