Cruthin

The Cruthin (Old Irish: [ˈkɾuθʲinʲ]) or Cruithne (Irish: [ˈkɾˠɪ(h)nʲə]) were a people of early medieval Ireland. Their heartland was in Ulster and included parts of the present-day counties of Antrim, Down and Londonderry. Although the evidence is that they were Gaels, their name is believed to be the Irish equivalent of *Pritanī, the reconstructed native name of the Celtic Britons, and Cruthin was sometimes used to refer to the Picts, but their relationship to these peoples is unclear.

The Cruthin comprised several túatha (tribal territories), which included the Dál nAraidi of County Antrim and the Uí Echach Cobo of County Down. These were part of the kingdom of Ulaid (Ulster). Early sources distinguish between the Cruthin and the Ulaid folk, although the Dál nAraidi later claimed in their genealogies to be na fír Ulaid, "the true Ulaid". The 17th century Leabhar na nGenealach claims that the Conaille, the Loígis and the Sogain are also of Cruthin descent.

By 773 AD, the annals had stopped using the term Cruthin in favour of the term Dál nAraidi, who had secured their over-kingship of the Cruthin.

For political reasons, some modern Ulster Scots unionists claim descent from the Cruthin and argue they were the original British inhabitants of Ulster. This has been rejected by historians and archaeologists (see #Modern politics and culture).