Satomi clan
The area around present-day Ichikawa has been inhabited since the Japanese Paleolithic period. Archaeologists have found stone tools dating to some 30,000 years ago. Numerous shell middens from the Jōmon period, and hundreds of burial tumuli from the Kofun period have been found in numerous locations around Ichikawa. During the Nara period, Ichikawa was the provincial capital of Shimōsa Province and is mentioned in the "Man'yōshū". During the Heian period, this area was the center of the rebellion by Taira Masakado. During the Sengoku period, it was the site of a major battles (Battle of Kōnodai) between the Satomi clan and the Later Hōjō clan.