The area of modern Niiza has been settled since prehistoric times. It was part of Shinra County within
Musashi Province in the
Nara period. Shinra County (新羅郡) was originally written with the same
kanji as the ancient Korean kingdom of
Silla, and the area was settled by immigrants from
Silla in 758 AD. The name was changed to Niikura County (新座郡) in the
Heian period. The town of Owada was created within Niikura District, Saitama with the establishment of the modern municipalities system on April 1, 1889. Niikura District was abolished in 1896, becoming part of
Kitaasachi District. On March 1, 1955, Owada annexed the neighboring village of Katayama becoming Niiza Town, which was raised to city status on November 1, 1970. ==Government==