During the early
Meiji period establishment of the municipality system on April 1, 1889, Sōsa District, consisting of one town (Fukuoka) and 13 villages were formed.
Timeline
On December 8, 1915 - Fukuoka was renamed Yōkaichiba.
On November 3, 1948 - the villages of Yoshida, Iitaka, Toyowa, and Hiyoshi (all from
Katori District) were redesignated as part of Sōsa District.
On March 31, 1954 - the town of Yōkaichiba expanded through annexation of the neighboring villages of Heiwa, Tsubakimi, Sosa, Toyosaka, Suga, Kyoko, Yoshida, Iitaka, and Toyowa.
On May 3, 1954 - the villages of Nanjo, Toyo, Shirahama, and Hiyoshi were merged to create the town of Hikari.
On June 1, 1954 - the villages of Kyowa and Toyohata were merged into the town of Asahi in
Kaijo District.
On July 1, 1954 - Yōkaichiba was elevated to city status.
On July 17, 1954 - the villages of Sakae and Noda were merged to create the town of
Nosaka, which left the district with two towns and no villages.
On January 23, 2006 - Nosaka was merged with the city of
Yōkaichiba to create the city of
Sōsa.[1]
On March 27, 2006 - Hikari was merged with the town of
Yokoshiba (from
Sanbu District) to create the town of
Yokoshibahikari (in Sanbu District). Therefore, Sōsa District was dissolved as a result of this merger.