In 1571, ascertaining that the corruption of Buddhist politics due to the military and political might of Enryaku-ji Temple's 4000 monk warriors was an obstacle to unification of the warring states, Nobunaga repeatedly demanded that Enryaku-ji Temple disarm, and in response to their resolute refusal surrounded Enryaku-ji Temple on September 12 and burned it down.
元亀2年(1571年)、延暦寺の僧兵四千人が強大な武力と権力を持つ僧による仏教政治腐敗で戦国統一の障害になるとみた信長は、延暦寺に武装解除するよう再三通達をし、これを断固拒否されたのを受けて9月12日(旧暦)、延暦寺を取り囲み焼き討ちした。