A knight vassal returned to his liege's castle with prisoners, bags of gold and other riches from all of his victories.

"Tell me of your battles," said the ruling liege.

"Well, sire, I have been robbing and stealing on your behalf for weeks, burning the villages of all your enemies in the north."

The liege was horrified. "But I have no enemies in the north," he said.

"Well," said the knight, "you do now.