While Tamemune stayed in Isa County (Hitachi Province), Nensai and Tamemune's younger brothers moved to Date County and called themselves as 'Date' to be the founder of Date clan.
為宗は伊佐郡(常陸国)に留ったが、念西と為宗の弟などが伊達郡に下って「伊達」を称し、伊達氏の祖となった。