豊後国
The castle was originally built in 1330, by Ōtomo Sadatoshi, Constable ("shugo") of Bungo Province, as a show of support to the Tachibana clan. Since it was in a tactically powerful location, looking down upon the port town of Hakata, the castle was fought over throughout the Sengoku period by the Ōtomo, Ōuchi, and Mōri clans.