The Cruithne were an ancient people who are occasionally mentioned in historical Irish sources, who lived within the British Isles during the Iron Age, arriving about 800 and 500 B.C. They were a matrilineal people, tracing royal lineage and inheritance through the female line and in pagan times had worshiped the mother-goddess of fertility.
By historical times they had come to reckon descent patrilineally, by the male line, hence their traditional descent from Conall Cearnach (“Conall of the Victories”), one of the legendary heroes from early Irish literature. Such Gaelic ancestral heroes, being the ultimate ancestors of all the ethnic groups of Gaeldom, are euhemerized deities (“gods made flesh”) from the ancient Celtic “Otherworld” of pre–Christian times. Conall Cearnach is ultimately a male-manifestation of Brigid (later St. Brigid), the original mother-goddess of the Cruithne
According to T. F. O’Rahilly’s historical model, the Cruithne were descended from the Priteni, who O’Rahilly argues were the first Celtic group to inhabit the British Isles, and identifies with the Picts of Scotland. They settled in Britain and Ireland between 700 and 500 BCE. They used iron and spoke a P-Celtic language, calling themselves Priteni or Pritani, which is the origin of the Latin word Britannia and the Old English words “Briton” and “British”.
More recent theories, supported by archaeological evidence, suggest that the Cruithne were a pre-Celtic people, and may have spoken a non-Indo-European language before the spread and dominance of Celtic culture in the British Isles. It is also suggested that these people were the descendants of the aboriginal Neolithic people of the isles.
Around 50 BCE Diodorus wrote of “those of the Pretani who inhabit the country called Iris (Ireland)”. The first reference to the name Pict is found in a Latin document dated 297 CE. It should be noted that Pytheas in about 325 BCE is credited with first recording the local name of the islands, in Greek as Prettanike – apparently in connection with the Cornish region – which Diodorus later rendered Pretannia.
In Britain these Priteni were absorbed by later invaders and lost their cultural identity except in the far north where they were known to the Romans as Picti, or “painted people,” on account of their practice of decorating their bodies with paint or tattoos (a practice which by then had died out among other Celtic tribes). In Ireland, too, the Priteni were largely absorbed by later settlers; but a few pockets of them managed to retain a measure of cultural, if not political, independence well into the Christian era. By then they were identified as Cruithne, P-Celtic linguistic descendants of the Priteni.
Among the Cruthnian tribes that survived were the Loíges (The Loigis were commonly referred to as the “Seven Septs of Leix.” There were several families of this tribe in historical times, including the O’Mores, O’Nolans, O’Dorans, O’Lawlors and O’Dowlings) and the Fothairt ( The Fothairt, or Fotharta, were mercenary tribes of the Laigin and possibly of Cruithin (Pict) origin. They were likely allies of the Ui Bairrche, explaining why they were also split into two major groups: the Fothairt in Chairn (alias Fothar Tíre, barony of Forth, Co. Wexford) and the Fothairt of Mag Fea (barony of Forth, Co. Carlow. In historical times the O’Mores were the leaders of the Fothairt of Mag Fea).
The name of the first of these tribes – modernized as Laois – has been revived and given to one of the counties of Leinster (formerly known as Queen’s County as a result of an attempted colonist plantation). By this stage in the 16th century the Cruithne were fully integrated into Gaelic Ireland and were indistinguishable from their neighbours.