Between the 5th and 12th centuries, an Irish sept claiming descent from Coirpre mac Néill ruled a barony of north Tethbae, called Cairpre Gabra. Their "Cairbre" territory corresponds to the barony of Granard in modern county Longford in Ireland.
Cairpre Gabra is a corruption of Irish: Cairbre Ua gCiardha and is best translated as “the descendants of Coirpre”. Coirpre (Irish: Cairbré) was eldest son of the Niall of the Nine Hostages the supposed ancestor of the southern Uí Néill. Tradition claims Coirpre mac Néill married a Fir Bolg princess named Mulreany and ruled all of North Longford from the Moat of Granard. Coirpre also owned tracts near Lough Erne and the Carbury barony in Sligo. The first Uí Néill successes in Leinster were probably due to this Coirpre, supposedly a high king of Ireland.
Ó Duígeannáin stated Cairbre Gabhra is identical to the ancient place "Ciarbre Ua gCiardha" disagreeing with O'Donovan's identification as Carbury (County Kildare barony)".
The territory was presumably a frontier colony of the Kingdom of Meath before the seventh century. An ancient folklore called "the Revolt of the Aithech Tuatha" named "the Tuath Glasraige” as ruling the territory around Granard and Lough Sheelin ("Irish: Tuath Glasraighe im Chairbre [Gabhra] agus im Loch Silinn") but nothing further is known about the tribe. Bracan mac Máine Mór probably resided at Rathbracken townland to the north of Granard. His descendants, the "Tuath Brecraighi", were defeated by the Cenél Coirpri in AD 751.