When the Kinmon no Hen (Conspiracy of Kinmon) occurred in 1864, in which the Choshu clan advanced its army toward Kyoto in order to ask for the Imperial Court's pardon for its lord and his son, the Imperial Court branded the Choshu clan as the Emperor's enemy for the reason that its soldiers fired at Kyoto Imperial Palace, and gave an imperial order to the bakufu to conquer the Choshu clan.
1864年（元治元年）には藩主父子の赦免などを求めて京へ軍事的に進行する禁門の変が起こると、朝廷は長州藩が京都御所へ向かって発砲を行ったことを理由に長州を朝敵とし、幕府に対して長州征討の勅命を下す。