In 1455 Kamakura kubo Shigeuji ASHIKAGA was attacked by Noritada IMAGAWA by order of Shogun Yoshimasa ASHIKAGA and ran away to domain of Shimousa-Koga.
康正元年（1455年）鎌倉公方足利成氏は将軍足利義政の命を受けた今川範忠に攻められ、下総古河へ逃れる。