On August 29th, 1869, he assumed the office of State Councilor and executed the establishment of the centralization of administrative power by the Meiji Government, including the return of lands and people to the Emperor, the abolition of feudal domains and establishment of prefectures.
明治2年7月22日(旧暦)（1869年8月29日）に参議に就任し、版籍奉還、廃藩置県などの明治政府の中央集権体制確立を行う。