"Sonpi Bunmyaku" (a text compiled in the fourteenth century that records the lineages of the aristocracy) says that he was the youngest brother of TAIRA no Masatake; however, according to "Hitachi no daijo fu," he was Masatake's elder brother.
『尊卑分脈』では末弟で平将武の弟であるが、『常陸大掾譜』では将武の兄としている。