Also, the insurrection of Masakado itself couldn't gain support of the samurai in Kanto, and the new government collapsed because Masakado died in battle in just 3 months.
また、将門の叛乱自体も、関東の武士たちの支持を得られず、わずか3ヶ月で将門が戦死して新政権は崩壊した。