They were the mystery merceneries. The faceless ones. The powerful onces. Wherever they went - together with their strange servants, people tended to back off, to turn the other way and leave the road clear.
No one knew where they came from and where they were really heading. They accepted work only for those who paid very well, and they didn't give a damn if they served in a just war or not. All they cared were to collect their payment at the end of the day. And when the war (or the money) were gone, so were they....