Tanistry

Historically the tanist was chosen from among the heads of the roydammna or "righdamhna" (literally, those of kingly material) or, alternatively, among all males of the sept, and elected by them in full assembly.

In Ireland, the tanistry continued among the dominant dynasties, as well as lesser lords and chieftains, until the mid-16th/early 17th century when it was replaced by English common law.

[5] The king or chief held office for life and was required by custom to be of full age, in possession of all his faculties, and without any remarkable blemish of mind or body.

However, perhaps more often a son of a rival branch of the dynasty), but not because the system of primogeniture was in any way recognised; indeed, the only principle adopted was that the dignity of chieftainship should descend to the eldest and most worthy agnate of the last ruler.

Tanistry evades the basic requirement of the hereditary monarchy, i.e. that the outcome of the succession is predictable, up to the identity of successor and next heirs, by genealogy.

The downside of the large group of eligibles was that increases in roydammna in each generation might lead to internecine dynastic civil war.

Their increasing consolidation via the annexation of the Kingdoms of Mide and Dublin, plus suborning neighboring states and lordships to vassalage, led to Tairrdelbach becoming the first of his dynasty to become High King.

The judicial resolution of the succession quarrel, directed by the English king, favoured the Balliols on the basis of primogeniture.

Robert the Bruce, grandson of the candidate who argued for tanistry, ascended the throne despite descending from a rather junior cadet line of the original Royal House.

A similar system operated in Wales, where, under Welsh law, any of the sons or brothers of the king could be chosen as the edling, or heir to the kingdom.

In the broadest sense, the name tanistry describes the functional principle that "the most talented male member of the royal dynasty should inherit the throne, commonly by murder and war".

[12][page needed] It is specifically used to describe the practical ramifications of the Turco-Mongol, as well as other Central Asian steppe nomad, principles of inheritance and succession.

Because all male members of the royal clan are considered to have equally legitimate claims on power, the ruler is the individual who eliminates competitors and re-subjugates the rest of the state formation.