However, as Masamune did not respect such relationship and old authorities of bakufu, he promoted a territorial expansion of the Date clan by beating the Nihonmatsu clan, a branch family of the Hatakeyama clan (one of the Ashikaga clan), and fighting against the Ashina clan and the Osaki clan, a former Oshu Tandai.
しかし、政宗はそうした親族血縁や幕府の旧権威を良しとせず、伊達氏の勢力拡大を推し進め、足利一門の畠山氏嫡流の流れを汲む二本松氏を打倒し、蘆名氏や旧奥州探題・大崎氏と戦った。