He was the younger brother of Tsugunobu, and their father was the Ōshū Fujiwara retainer Satō Motoharu.

Whilst travelling to Kyushu to escape from the troops of his brother Yoritomo, Yoshitsune and his forces were beset by the monks of Zo-o-no, and were facing defeat.

)[2] Disguised as Yoshitsune, Satō challenged and fought the group's pursuers, killing or wounding around twenty men.

[3] His widow, Kaede, along with her sister-in-law Wakazakura, attempted to comfort his grieving mother by presenting herself wearing her late husband's armour.

[5] A popular story regarding Satō Tadanobu's death involves him being attacked whilst playing a game of go.