primogeniture, in law, the rule of inheritance whereby land descends to the oldest son. Under the feudal system of medieval Europe, primogeniture generally governed the inheritance of land held in military tenure (see feudalism; knight). The effect of this rule was to keep the father's land for the support of the son who rendered the required military service. When feudalism declined and the payment of a tax was substituted for military service, the need for primogeniture disappeared. In England, consequently, there was enacted the Statute of Wills (1540), which permitted the oldest son to be entirely cut off from inheriting, and in the 17th cent. military tenure was abolished; primogeniture is, nevertheless, still customary in England. In the United States primogeniture never became widely established. For other traditional types of inheritance, see gavelkind; borough-English.