Primogeniture refers to a couple’s firstborn child and to the related system of inheritance in which that child inherits their estate when the property-owning parent dies. The concept is legally applied to a married couple and their legitimate child. The system is closely associated with European royalty and nobility. Because property ownership was almost exclusively limited to men, it almost always applied to transmission between men. Notably, upon a king’s death, his oldest son would inherit the position of king as well as his property. One main reason for the system was to preserve the integrity of the estate rather than see it divided among multiple heirs.

Inheritance through the male line is called agnatic primogeniture. In such a system, if the heir’s mother outlived her husband, the son was often required to support his mother during her life. If the heir was a minor, the mother might serve as regent, although this role sometimes was occupied by one of the late father’s brothers. Similarly, if there was no male child, another male relative might inherit. However, in some areas of the world, women did have property rights and held their property separate from that of their husband; upon the mother’s death, the property would pass to her oldest daughter. This variant is called matrilineal primogeniture.