Tanistry

Tanistry was a system of inheritance practised by the Gaelic nobilities of Ireland, the Isle of Man, and parts of modern Scotland. It was distinctive in having an elected heir known as the tanist (; ; ). This system was used to select the Chiefs of the Name (head of a clan) and the rulers of the various Gaelic kingdoms in Ireland and in Scotland.

When the chief or king died they were immediately succeeded by the tanist, who had typically been elected years earlier. A new election was then held to select the next tanist. This differs from other systems of elective inheritance, in that an heir was elected in advance of a vacancy, not after the vacancy arose. Valid candidates for the election were restricted to male members of the title holder's sept (extended family); the exact eligibility criteria differed between Ireland and Scotland. The electorate was identical to the set of valid candidates i.e. potential heirs would select a tanist from amongst themselves.