When that Miura clan was defeated by the Adachi and Hojo clans during the Battle of Hoji in 1247, Moritoki SAHARA of the clan stood on the side of Hojo clan and later became the soryo of the Miura clan.
その三浦氏が、1247年（宝治元）の宝治合戦で、安達氏・北条氏に滅亡させられたとき、一族の佐原盛時は北条氏について、後に三浦氏の惣領となった。