Masakado died in the battle against TAIRA no Sadamori and FUJIWARA no Hidesato on February 14 of the same year, 940, whereupon his influence immediately ceased.
同年2月14日に平貞盛・藤原秀郷らとの合戦で将門が討ち死にすると、将門の勢力は一気に瓦解した。