Banditry

Most of the war chronicles I've read were about valiant knights and their glorious deeds. But I know that isn't what war's really like. Many battles are fought by mercenaries, loyal to their king or knyaz for only as long as he's paying them. And when he stops, they start looking for a new opportunity. They don't always find it, though, and they become bandits, turning against the very people they were meant to protect. They rob and destroy villages, they kill and harass peasants. And they're much worse than regular troublemakers, because they are usually skilled, and also numbed by the many battles they fought. There are places where they're the ones who hold all the power, and terrorise commoners and rulers alike.