Sasebo Naval District

In 1883, the then Lieutenant Commander Tōgō Heihachirō nominated what was a tiny fishing village as the ideal location for a naval base.

Sasebo was designated as the "Third Naval District" (第三海軍区, dai-san kaigunku), and its harbor was dredged, a breakwater constructed and docking, coaling and repair facilities for warships were established, and the military base was officially opened in 1889.

Sasebo was the closest ship repair facility for the Imperial Japanese Navy to the combat zones of the Russo-Japanese War and saw considerable activity during that conflict.

In 1934, the Tomozuru capsized off Sasebo with loss of most of its crew, and leaving behind serious questions about the basic design of many Japanese warships.

The Imperial Japanese Navy had some 60,000 people working in the dock yard and associated naval stations at the peak of World War II, outfitting ships, submarines and aircraft.