Primogeniture

Primogeniture (/ˌpraɪməˈdʒɛnɪtʃər, -oʊ-/) is the right, by law or custom, of the firstborn legitimate child to inherit all or most of their parent's estate, as well as succeed their parent as the ruler of a state.

Primogeniture stands in contrast to shared inheritance among all or some children, any illegitimate child or any collateral relative. In most contexts, it means the inheritance of the firstborn son (agnatic primogeniture). It can also mean by the firstborn daughter (matrilineal primogeniture), or firstborn child (absolute primogeniture).

Research shows that authoritarian regimes that rely on primogeniture for succession were more stable than forms of authoritarian rule with alternative succession arrangements. Scholars have linked primogeniture to a decline in regicide, as clear rules of succession reduce the number of people who could (absent a coup d'état) replace a ruler, thus making it less desirable to cause the death of the monarch.

The common definition given is also known as male-line primogeniture, the classical form popular in European jurisdictions among others until into the 20th century. In the absence of male-line offspring, variations were expounded to entitle a daughter or a brother or, in the absence of either, to another collateral relative, in a specified order (e.g., male-preference primogeniture, Salic primogeniture, semi-Salic primogeniture). Variations have tempered the traditional, sole-beneficiary, right (such as French appanage) or, in the West since World War II, eliminate the preference for males over females (absolute male-preference primogeniture). Most monarchies in Europe have eliminated this, including: Belgium, Denmark, Luxembourg, Netherlands, Norway, Sweden and the United Kingdom. The exceptions are Spain and Monaco (male-preference primogeniture) along with Liechtenstein (agnatic primogeniture).

English primogeniture endures mainly in titles of nobility: any first-placed direct male-line descendant (e.g. eldest son's son's son) inherits the title before siblings and similar, this being termed "by right of substitution" for the deceased heir; secondly where children were only daughters they would enjoy the fettered use (life use) of an equal amount of the underlying real asset and the substantive free use (such as one-half inheritance) would accrue to their most senior-line male descendant or contingent on her marriage (moieties); thirdly, where the late estate holder had no descendants his oldest brother would succeed, and his descendants would likewise enjoy the rule of substitution where he had died. The effect of English primogeniture was to keep estates undivided wherever possible and to disinherit real property from female relations unless only daughters survived in which case the estate thus normally results in division. The principle has applied in history to inheritance of land as well as inherited titles and offices, most notably monarchies, continuing until modified or abolished.

Other forms of inheritance in monarchies have existed or continue. Currently, succession to the Saudi Arabian throne uses a form of lateral agnatic seniority, as did the Kievan Rus' (see Rota system), the early Kingdom of Scotland (see Tanistry), the Mongol Empire (see lateral succession) or the later Ottoman Empire (see succession practices).

Some monarchies have (at least in principle) no element of heredity in their laws of succession at all and monarchs are elected. The Holy Roman Emperor was chosen by a small number of powerful prince electors from among Imperial magnates, while kings of Poland-Lithuania were elected directly by the nobility. Intermediate arrangements also exist, such as restricting eligible candidates to members of a dynasty (as is currently done in Cambodia).

Tanistry refers to inheritance by "the most talented male member of the royal dynasty."