Crimthann mac Fidaig

Importantly, he is included in the Baile Chuinn Chétchathaig (summary), and is thus the last High King of Ireland from Munster until Brian Bóruma, over six hundred years later.

In addition to having his reign described by Geoffrey Keating and mentioned in the Annals of the Four Masters, Crimthand Mór mac Fidaig also plays a major role in many stories belonging to the Cycles of the Kings.

[4] There appears to be little doubt that it existed,[5] and British archaeologists and linguists have attempted to identify it with a number of sites in Cornwall and in Wales as well, for example, Din Draithou,[6] which is phonetically similar.

[7] It may also be associated with Dind map Letháin, a colonial fortress constructed by the related Uí Liatháin, earlier form Létháin,[8] kingdom of Munster, who is known to have been active in Britain for centuries.

As grandchildren of Dáire Cerbba (Cearba, Cearb) in most sources (e.g., Rawlinson B 502), also an ancestor of the Uí Liatháin and Uí Fidgenti, the brother and sister are sometimes regarded as belonging to an early branch of the Eóganachta which later became peripheral or became extinct, although it is more likely that all descendants of Dáire Cerbba belong to a distinct people, possibly the Dáirine, which may be hinted at in an obscure Old Irish poem by Flann mac Lonáin,[11] although in the Banshenchas Mongfind is called "Mongfind of the Érnai" (Érainn),[12] a people in any case related to the Dáirine.

A passage in Rawlinson B 502 declares that Dáire Cerbba was born in Mag Breg (Brega), Mide,[13] much of which probably remained Érainn or Dáirine territory at the time of his supposed floruit.

Later political genealogies may remove this generation to make the monarch appear closer to the historical Eóganachta, his natural kindred having mostly fallen into obscurity.

Byrne reproduces one of these (2001), and does not give his source, probably Laud 610, in which the father of Crimthand Mór is a certain Láre Fidach, son of Ailill Flann Bec.