In 1189, Tamemune took part in the campaign with his younger brothers Tameshige UENO, Suketsuna DATE, and Tameie DATE for the Battle of Oshu (Oshu-Seibatsu [Kamakura bakufu's military campaign against the Fujiwara of northern Japan]) launched by MINAMOTO no Yoritomo to hunt down and kill FUJIWARA no Yasuhira.
文治5年（1189年）、源頼朝が藤原泰衡追討のために行った奥州合戦（奥州征伐）に、弟の殖野為重、伊達資綱、伊達為家とともに従軍。