Primogeniture () 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)."primogeniture, n.". OED Online. September 2019. Oxford University Press. https://www.oed.com/view/Entry/151368 (accessed 26 October 2019). 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.
Description 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, Liechtenstein, Luxembourg, Netherlands, Norway, Sweden and the United Kingdom. The exceptions are Spain and Monaco (male-preference 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."
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.
Order of succession in monarchies
Absolute primogeniture
Absolute, equal, (full) cognatic or lineal primogeniture is a form of primogeniture in which sex is irrelevant for inheritance; the oldest surviving child without regard to sex inherits the throne. Mathematically this is a depth-first search. See Example 3.7, p. 93.
History No monarchy implemented this form of primogeniture before 1980,SOU 1977:5 Kvinnlig tronföljd, p. 16. when Sweden amended its Act of Succession to adopt it in royal succession. This displaced King Carl XVI Gustaf's infant son, Prince Carl Philip, in favor of his elder daughter, Princess Victoria. Several monarchies have since followed suit: the Netherlands in 1983, Norway in 1990 (not retroactively), Belgium in 1991, Denmark in 2009, Luxembourg in 2011, and Liechtenstein in 2026 (also not retroactively). In 2011, the governments of the 16 Commonwealth realms which had a common monarch—Elizabeth II at that date—announced the Perth Agreement, a plan to legislate changes to absolute primogeniture. This came into effect with the necessary legislation on 26 March 2015. Other monarchies have considered changing to absolute primogeniture: With the birth of Infanta Leonor of Spain on 31 October 2005 to the then heir apparent Felipe, Prince of Asturias, and Princess Letizia, the Spanish Prime Minister José Luis Rodríguez Zapatero reaffirmed the intention of the government to institute, by amendment of the Spanish constitution, absolute primogeniture. Zapatero's proposal was supported by the leader of the main opposition party, the conservative Partido Popular, making its passage probable. However, Zapatero's administration ended before an amendment was drafted, and the succeeding governments have not pursued it. The Prince counseled reformers that there was plenty of time before any constitutional amendment would need to be enacted because the expectation was to leave him next in line to succeed his father despite his elder sisters' continued status as dynasts; equal primogeniture was expected to apply first to his children. Felipe succeeded to the throne as Felipe VI upon his father's abdication in 2014, by which time he had two daughters. Felipe VI has no son that would, absent the constitutional amendment, displace Leonor as heir. In July 2006, the Nepalese government proposed adopting absolute primogeniture, but the monarchy was abolished in 2008 before the change could be effected. In Japan, it was debated whether to adopt absolute primogeniture, as Princess Aiko was the only child of Emperor Naruhito. The 2006 birth of Prince Hisahito, a son of Prince Akishino (the younger brother of Naruhito, and next in line to the Chrysanthemum Throne) suspended the debate.
Monaco, the Netherlands, and Norway also deviated from traditional primogeniture in the late 20th or early 21st century by restricting succession to the crown to relatives within a specified degree of kinship to the most recent monarch.
Agnatic primogeniture
Agnatic primogeniture or patrilineal primogeniture is inheritance according to seniority of birth among the sons of a monarch or head of family, with sons inheriting before brothers, and male-line male descendants inheriting before collateral male relatives in the male line, and to the total exclusion of females and descendants through females.Tronföljd, Nordisk familjebok, vol. 30 (1920) This exclusion of females from dynastic succession is also referred to as application of the Salic law.
Agnatic-cognatic primogeniture
Another variation on agnatic primogeniture is the so-called semi-Salic law, or "agnatic-cognatic primogeniture", which allows women to succeed only at the extinction of all the male descendants in the male line of the particular legislator. Such were the cases of Bourbon Spain until 1833 and the dominions of Austria-Hungary, as well as most realms within the former Holy Roman Empire, i.e. most German monarchies. This was also the law of Russia under the Pauline Laws of 1797 and of Luxembourg until absolute primogeniture was introduced on 20 June 2011.
There are various versions of semi-Salic law also, although in all forms women do not succeed by application of the same kind of primogeniture as was in effect among males in the family. Rather, the female who is nearest in kinship to the last male monarch of the family inherits, even if another female of the dynasty is senior by primogeniture. Among sisters (and the lines of descendants issuing from them), the elder are preferred to the younger. In reckoning consanguinity or proximity of blood the dynasty's house law defines who among female relatives is "nearest" to the last male.
Male-preference (cognatic) primogeniture
Male-preference primogeniture (in the past called cognatic primogeniture) provides that a dynast's sons and their lines of descent all come before the dynast's daughters and their lines. Older sons and their lines come before younger sons and their lines. It accords succession to the throne to a female member of a dynasty if and only if she has no living brothers and no deceased brothers who left surviving legitimate descendants. Then, older daughters and their lines come before younger daughters and their lines, thus a daughter inherits before her uncle and his descendants.
It was practised in the succession to the different medieval kingdoms of the United Kingdom and the Iberian Peninsula. The United Kingdom changed it to absolute primogeniture (to the eldest legitimate child, regardless of sex), through the Succession to the Crown Act 2013 (effective March 26, 2015). This rule change was simultaneously adopted by the other Commonwealth realms that have the same monarch as their head of state. With respect to hereditary titles, it is usually the rule everywhere in Scotland and baronies by writ in England, but usually these baronies by writ go into abeyance when the last male titleholder dies leaving more than one surviving sister or more than one descendant in the legitimate female line of the original titleholder. In England, Fiefs or titles granted "in tail general" or to "heirs general" allow older sons to succeed before younger sons, but daughters are considered equal co-heirs to each other, which can result in abeyance. In the medieval period, actual practice varied with local custom. While women could inherit manors, power was usually exercised by their husbands (jure uxoris) or their sons (jure matris). However, in Scotland, neither Salic law or any of its variations have ever been practised, nor abeyance, and all the hereditary titles are inherited through male-preference primogeniture, where in the extinction of a male line, the eldest sister automatically receives the titles, and rules in her own right, not in the right of her son. A famous example of this is Marjorie, Countess of Carrick, mother of Robert the Bruce, who was the Countess of Carrick in her own right.