At first the group had been formed to counter the group of Sonno Joi (19th century slogan advocating reverence for the Emperor and the expulsion of foreigners) and the Choshu clan; after the Sonno Joi group had been purged by the August 18 Coup (the Bunkyu Coup of 1863), the powerful lords including the three of the Ichikaiso Government participated in the Sanyo-kaigi (the Councilor Council in the Court) which had been set up so that the Tokugawa Shogunate and the Imperial Court cooperate on dealing with impending matters; although the Sanyo-kaigi was unraveled soon, the three politicians had maintained their power and dominated over the politics in Kyoto until the Overthrow of the Shogunate and the Decree for the Restoration of Imperial Rule (1867).
この体制は尊皇攘夷・長州藩への対抗を通じて形成され、八月十八日の政変以降、尊皇攘夷派が退潮し、さらに公武合体論に基づく有力諸侯による参預会議が崩壊したのち、王政復古の大号令による倒幕派クーデタまでの京都政界をほぼ支配した。