In the battle of Hitachi in 1106, he fought against MINAMOTO no Yoshikuni, whose base was in Shimotsuke Province, with his grandfather Yoshimitsu, his father Yoshinari, and his maternal grandfather TAIRA no Shigemoto and prevented Yoshikuni from pervading his power in Hitachi.
1106年の常陸合戦の際には祖父の義光・父の義業、外祖父の平重幹とともに下野国を地盤とする源義国と戦い、義国の勢力の常陸への浸透を防いだ。