上総国
Chōsei is located in former Kazusa Province. The villages of Takanehongo, Yatsumi, Ichimatsu were established with the creation of the modern municipalities system on April 1, 1889.Chōsei Village was created on November 3, 1953 from the merger of these hamlets. Some minor territorial adjustments were made with neighboring Ichinomiya in 1954 and 1955.