Akashi developed as a castle town, and many relics of the Jōmon and Yayoi periods remain on the nearby hills. Artifacts of the Jōmon period (c. 10,500–c. 300 bce; a hunting and gathering society) include pottery with distinctive cord impressions. During the Yayoi period (c. 300 bce–c. 250 ce) immigrants from Korea introduced irrigation techniques and bronze and iron implements.
Before World War II, Akashi was a thriving city, its economy based on the aircraft industry, but half of the population was lost to air raids in the old part of the city during the war. The heavy steel industry developed during the Korean War and revived Akashi as an industrial and residential district. The city was formerly a fishing centre, but the yield of marine products subsequently decreased because of overfishing and marine pollution. The Japanese standard-time meridian, 135° E, passes through the city. The northern terminus of the Akashi Strait Bridge is just southeast of Akashi in southern Kōbe. Pop. (2010) 290,959; (2015) 293,409.