On July 26, 1192, Yoritomo, who had assumed the position of 'Seii taishogun' (literally, "great general who subdues the barbarians"), established the Kamakura Bakufu (Japanese feudal government headed by a shogun) and Tsunetaka assumed the position of Nakatsukasanojo (Secretary of Ministry of Central Affairs) some time before September 17, 1192.
建久3年（1192年）7月26日に、頼朝は征夷大将軍に任ぜられ鎌倉幕府を開き、同年9月17日までに経高は中務丞に任ぜられている。