Judges 8:21
"Then Zebah and Zalmunna said, Rise thou, and fall upon us: for as the man is, so is his strength. And Gideon arose, and slew Zebah and Zalmunna, and took away the ornaments that were on their camels' necks."
During the conquer of the Midianites, Gideon captured their princes and put them in prison until he finished the battle.