Derbfine

The derbfine was an Irish agnatic kinship group and power structure as defined in the law tracts of the eighth century. Its principal purpose was as an institution of property inheritance, with property redistributed on the death of a member to those remaining members of the derbfine. Comprising all the patrilineal descendants over a four-generation group with a common great-grandfather, it gradually gave way to a smaller three-generation kinship group, called the gelfine.

Within a clan, on the death of its chief or king, the surviving members of its derbfine would elect from their number a new chief and/or elect his successor, or Tánaiste (in English, his Tanist). A larger number of clan members, either allies or cousins who were too distantly related to be members of the derbfine, would not have a direct say in such an election. The frequent recitations of a clan's genealogy by its bards was therefore a reminder of who was currently in or out of the clan's derbfine as much as it was a claim to ancient lineages.

Professor F.J. Byrne of UCD also identified an indfine system used in some clans before 1000AD, with membership going back to a common great-great-great-grandfather, perhaps necessary at a time of frequent warfare.

The inheritance of the Norman royal line on the death of King Stephen and his succession by his cousin Henry II is an example of the derbfinal system working outside Ireland. Stephen's son was disinherited by consent, Henry was chosen as tánaiste or deputy chief, and succeeded to the English throne in 1154. The system was again attempted during the incapacity of Henry VI, when the House of York obtained the support of some royal cousins to take the throne in 1461. By then the norm in Europe was the system of primogeniture, which led on to the turbulent succession crises and policies of Henry VIII in 1527-36.

The system of male-line descent in an identity-group with a common great-grandfather is still found in countries like Iraq where it is known as the Khamsa system.

References

• Marie Therese Flanagan, Irish Society, Anglo Norman Settlers, Angevin Kingship (OUP 1998)
• FJ Byrne, Irish Kings and High-Kings (various reprints)

See also

• Tanistry
• Clan
• Early Irish Law