Kōzuke Province

During the 4th century AD, (Kofun period) the area of modern Gunma and Tochigi prefectures were known as Keno or Kenu (毛野), literally "hairy field", but used as ateji for 食野 or "food field" in reference to an imperial agricultural area.

Per the Nara period Taihō Code, these provinces became Kamitsukeno-no-kuni (上毛野国) and Shimotsukeno-no-kuni (下毛野国).

At some point, the no meaning "field" was reanalyzed as the possessive particle no, resulting in shortened names (without the Kuni (国) or "province" portion) of Kamitsuke and Shimotsuke.

[2][3][4] During the Heian period, from the year 811, Kōzuke (along with Hitachi and Kazusa) was one of the three provinces where an Imperial Prince was designated as nominal ruler.

The Nakasendō and the Mikuni Kaidō highways passed through the province, and numerous post stations were established.

Map of Japanese provinces (1868) with Kōzuke Province highlighted
Hiroshige ukiyo-e " Kōzuke " in "The Famous Scenes of the Sixty States" (六十余州名所図会), depicting Mount Haruna Under Snow