Terumune's childhood name was Hikotaro (彦太郎) later Sojiro (総次郎). He was born a warrior since his family is often in conflict with its neighbors. In 1568, Terumune attacked
Nihonmatsu Castle against
Nihonmatsu Yoshitsugu, outnumbered and defeated, Yoshitsugu pretended to surrender. Terumune fought against the
Mogami Yoshiaki twice in different years, 1574 and 1578, in both battles, his wife, who also Yoshiaki sister,
Yoshihime, advanced to the middle of the battlefield to create a peace treaty. Later in 1578, Terumune succeeded his father
Harumune; and he became the sixteenth head of the
Date clan of
Mutsu Province. Records show that Nobunaga cultivated a close relationship with Terumune. The daimyo often confided in him affairs of the state through letters. During his campaigns unifying Japan, he sent Terumune a letter boasting how he annihilated tens of thousands in
Echizen and
Kaga. When
Oda Nobunaga was assassinated in 1582, Terumune gave his clan's support to
Toyotomi Hideyoshi in the power struggle which followed. An account cited him as party to the negotiation with a local rival called
Hatakeyama Yoshitsugu. At this time, his son
Date Masamune appear to be leading the clan. In 1585, Yoshitsugu was invited to a feast after an alliance was forged. A day after, when Masamune took the guest hunting, the latter's men abducted the undefended Terumune. Yoshitsugu stabbed Terumune to his death when he panicked as Masamune and his men caught up with him by the banks of the Abukuma River. A version of this account stated that Terumune was taken to the kidnapper's fort, where he was slain during Terumune's siege. ==Family==