Agatanonushi (territorial ruler) (県主)

The term "agatanonushi" refers to a post or kabane (hereditary title) of Yamato sovereignty (the ancient Japan sovereignty) before the introduction of the ritsuryo system (a system of centralized government based on the ritsuryo code).

Agata was a kind of province over which Yamato sovereignty had direct control.
Agata is said to have been a province that ranked below ryoseikoku (a kind of province)
But there is also a theory that ryoseikoku and agata were treated equally in ancient times. Agata is considered to have been originally a toparchy governed by a local ruling family in ancient times. However, most of the details are unknown because it was a province in a time when the Japanese nation had not yet been systematized under the ritsuryo codes. Agatanonushi gave his great loyalty to Yamato sovereignty, unlike kuninomiyatsuko (local ruling families in ancient Japan) that are said to have been appointed as rulers of the regions formerly governed by them. Agatanonushi is considered to have governed the region as a deputy of Yamato sovereignty. Agatanonushi concentrated in western Japan, while there were only few agatanonushi in eastern Japan. Yamato sovereignty made the local ruling families belonging to it govern their territory in eastern Japan where its ruling system was established in a later period than in western Japan. They were appointed as kuninomiyatsuko who were invested with almost full power. On the other hand, the system to rule the regions formerly governed by the local ruling families was built by Yamato sovereignty from early on in western Japan where the sovereignty was established during an early period, which was the reason why agatanonushi concentrated in western Japan.

The kabane itself had existed even after the introduction of Yakusa no Kabane, the eight honorary titles, and the ritsuryo system. In some cases, agatanonushi has been used as a title also in modern times, and the Kamo agatanonushi family of Kamo-jinja Shrine is a prime example of them.