"Sonpi Bunmyaku" (a text compiled in the fourteenth century that records the lineages of the aristocracy) says he was the seventh son and an elder brother of TAIRA no Masatame; however, according to "Hitachi no daijo fu," he was Masatame's younger brother.
『尊卑分脈』では七男で平将為の兄であるが、『常陸大掾譜』では将為の弟となっている。