Itagaki, Taisuke (tĪˈsōkē ētäˈgäkē) [key], 1837–1919, Japanese statesman. After taking part in the Meiji restoration, he became (1869) a councillor of state. A samurai of Tosa, he opposed domination of the government by the Choshu and Satsuma clans. He helped launch a campaign for an elective assembly that led to the establishment of a senate in 1875 and, in 1878, of prefectural assemblies, with advisory powers only. As a means to achieve constitutional reform, Itagaki founded (1877) the Risshisha [Society of Independence] and set up (1881) the Jiyuto [Liberal] party, a forerunner of the Seiyukai. He was home minister under Hirobumi Ito and in 1898 was associated with Shigenobu Okuma in an attempt to form a party government.