In addition, a letter sent by Masakado to FUJIWARA no Tadahira, whom Masakado regarded as his lord, says, "FUJIWARA no Tamenori, son of Korechika, was oppressing Haruaki taking advantage of the authority of the government. Having received a petition from Haruaki, I went to the local government office of Hitachi Province to confirm the circumstances. Tamenori then organized an army, allying with TAIRA no Sadamori, and attacked me. Consequently I defeated them."
また、将門が私君藤原忠平へ送った書状によると「維幾の子藤原為憲が公の威光をかさに着て玄明を圧迫しており、玄明の愁訴によって事情を確かめに常陸国府に出向いたところ、為憲は平貞盛と結託して兵を集めて挑んでまいりましたので、これを撃破したのでございます。」とある。