After the Johei and Tengyo War, TAIRA no Masakado appointed persons to the kokushi of eight provinces in the Kanto region in the capacity of the new emperor, but he appointed 'Hitachi no suke' (assistant governor of Hitachi Province) and 'Kazusa no suke' (assistant governor of Kazusa Province) to the kokushi of Hitachi and Kazusa respectively.
承平天慶の乱において平将門が新皇として関東八ヶ国の国司を任命した際も、常陸と上総の国司は「常陸国」「上総国」を任命している。