According to 'the article of November 3, 938' of "Honcho seiki" (Chronicle of Imperial Reigns), a warrant to search and capture Masatake was issued in four provinces of Suruga, Izu, Kai and Sagami, which tells that Masatake had been exerting overwhelming influence based in Izu and Sagami before Masakado launched the Johei and Tengyo War.
『本朝世紀』の「天慶元年（938年）11月3日の条」によると、駿河国・伊豆国・甲斐国・相模国の四ヶ国に将武の追捕令が発せられており、将門が承平天慶の乱をおこす以前から伊豆・相模辺りを拠点に猛威を奮っていたとみられている。