Because the local government of Hitachi refused his demand and declared war, Masakado had no choice but to fight, and even though Masakado was leading a force of only slighhtly more than 1,000 men, he quickly defeated the local government's army of 3,000 men, and the Hitachi no suke, FUJIWARA no Korechika, was forced to surrender.
常陸国府はこれを拒否するとともに宣戦布告をしたため、将門はやむなく戦うこととなり、将門は手勢1000人余ながらも国府軍3000人をたちまち打ち破り、常陸介藤原維幾はあっけなく降伏。