Merchet

A merchet was a fine paid on a marriage during the Middle Ages in England. The word derives from the plural form of daughter, merched, in old Welsh. A peasant would pay a merchet to his lord upon the marriage of a woman. The justification for this was that when a woman married, her lord was losing a worker. Usually the bride's father would pay, as buying the right to give his daughter away.

There is an unsubstantiated theory that relates this fine to droit du seigneur

...
Wikipedia