According to a document dated circa 1291, a "wasteland belonging to no one" was developed during the Manju era (1024–1028) and was donated to Kampaku (de facto ruler of Japan) Fujiwara no Yorimichi to break free from the provincial government's control.
Another document states that its founder was Taira no Suemoto, the Dazai Daigen (high-ranking official of the administrative center of Kyūshū).
In 1029, Taira no Suemoto even raided the government office of the neighboring Ōsumi Province but a fragmentary sources suggest that he was not punished severely.
[1] In 1203, Shimazu Tadahisa was ousted from his positions as a jitō of the estate and the military governor of the three provinces because his relative Hiki Yoshikazu was annihilated by the Hōjō clan.
The Nagoe branch family of the Hōjō clan maintained the post of jitō in Ōsumi until the end of the Kamakura period.
Because the Nagoe family kept the position of the jitō of the estate in Ōsumi, the military governor had to devote much effort to consolidate power.
As a result of the Jōkyū War, Satsuma's Kawanabe District came under the control of the Tokusō (mainline) family of the Hōjō clan.
Because the military government and the estate in Ōsumi remained distinct entities, the Shimazu clan had much trouble regaining control over the province and eventually collapsed.