FUJIWARA no Hidehisa, a younger brother of FUJIWARA no Hidehira, moved out to reside in the Tosaminato region, and started a branch family known as the Tosa clan (the Tosa-Fujiwara clan).
藤原秀衡の弟藤原秀栄は、分家して、十三湊に住み十三氏（十三藤原氏）を名乗った。