was the founder of the Shimazu samurai clan. According to a record of his life, he was reportedly born in Sumiyoshi Taisha in Osaka. He was initially Koremune Tadayoshi (惟宗忠久) but after being given the territory of Shimazu, Hyūga Province to rule from by Minamoto no Yoritomo, he took the name of Shimazu. Tadahisa was a son of the Shogun Minamoto no Yoritomo (1147–1199) by the sister of Hiki Yoshikazu. He married a daughter of Koremune Hironobu, descendant of the Hata clan, whose name Tadahisa at first took.