 The area around present-day Odawara has been settled since prehistoric times, and archaeological evidence indicates that the area had a high population density in the Jōmon period.From the Ritsuryō system of the Nara period, the area became part of Ashigarashimo District of Sagami Province.It was divided into "shōen" during the Heian period, mostly controlled by the Hatano clan and its branches.