The Jo clan (the Taira clan), which was a noble family descended from TAIRA no Shigemori, the second son of TAIRA no Kunika, had controlled Echigo Province under the Taira clan government.
城氏(平氏)は平国香の次男平繁盛の流れを汲む名族で、平氏政権期において越後国を支配していた。