Primogeniture is inheritance by the first-born of the entirety of a parent's wealth, estate or office, or in the absence of children, by collateral relatives. It is often used in monarchies.
Agnatic primogeniture is inheritance by the oldest surviving male child, and if there are none then by collateral relatives, with female inheritance not permitted.
Male primogeniture is inheritance by the eldest surviving male child, but females may inherit provided the subject has no sons.
Cognatic primogeniture is inheritance by the oldest surviving child without regard to gender, sometimes called lineal primogeniture. The first country to adopt full cognatic primogeniture was Sweden in 1980. The beneficiary of this was Victoria of Sweden. Several other monarchies have since followed, such as Belgium, the Netherlands and Norway (with Princess Ingrid Alexandra of Norway as second in line to the throne after her father, Crown Prince Haakon). In Japan, there are currently debates over whether to adopt cognatic primogeniture, as Princess Aiko is the firstborn of Crown Prince Naruhito.
A special case of primogeniture exemplified in the French royal milieu, the Salic Law (attributed to the Salian Franks) forbade any inheritance of a crown through the female line. This accounts for the dispute over the legitimate successor of Charles IV of France (Edward III of England or Philip VI of France), the loss of Hanover to Ernest I from the United Kingdom upon the accession of Queen Victoria in 1837, the separation of the ducal house of Luxembourg from that of the Netherlands, and partially explains the role of Carlism in Spain.
In England, primogeniture was mandatory for inheritance of land. Until the Statute of Wills was passed in 1540, a will could only control the inheritance of personal property. Real estate (land) passed to the eldest male descendant by operation of law. The statute added a provision that a landowner could "devise" land by the use of a new device called a "testament".
Arguments in favour of primogeniture
Primogeniture prevents the subdivision of estates and the requirement to sell property (for example, if two children inherit a house and one cannot afford to buy out the other's share). In England the younger sons of the nobility, having no prospect of inheriting land or property, were obliged to seek careers in the Church, the Armed Forces or in Government. In the late 17th and early 18th Centuries, many specifically chose to leave England for Virginia in the Colonies. Most, if not almost all, of the early Virginians who were plantation owners were such younger sons who had left England because of primogeniture laws. These Founding Fathers of the United States were nearly universally descended from the landed gentry of England, with many being descended from English Kings of the late 14th and early 15th Centuries, especially through the prodigious offspring of Edward III of England.
Arguments against primogeniture
The fact that the eldest son "scooped the pool" often led to ill-feeling amongst younger sons (and of course daughters). Through marriage, estates were combined and some nobles achieved wealth and power sufficient to pose a threat even to the crown itself.
Other methods of succession