Tirkeeran

Tirkeeran Tír Mhic Caoirthinn (Irish)
Location of Tirkeeran, County Londonderry, Northern Ireland.
Sovereign state	United Kingdom
Country	Northern Ireland
County	Londonderry

Tirkeeran (from Irish Tír Mhic Caoirthinn, meaning "land of Cartin") is a barony in County Londonderry, Northern Ireland. It connects to the north-Londonderry coastline, and is bordered by four other baronies: Keenaght to the east; Strabane Lower to the south-east; North West Liberties of Londonderry to the west; Strabane Upper to the south.

Tirkeeran derives its name from the territory of the Airgiallan clan; Ui Mhic Carthainn (MacCarthain), one of the earliest tribes in the area based to the south-east of Locha Febail (Lough Foyle). The Ui Mhic Carthainn are claimed to descend from Forgo mac Carthainn, the great-great-grandson of Colla Uais.

Dunchad mac Ultain is cited as king of the Ui Meic Cairthinn in 677, when he was killed by the Cenél nEóghain king, Mael Fithrich. It was around this period that the Cenél nEóghain were attempting to expand eastwards from their homeland in Innishowen, in modern-day County Donegal and into central Ulster. Eventually the Cenél nEóghain crushed the power and independence of the Ui Mhic Carthainn and subjugated them, however it would remain in some minor form until the end of the eleventh century when the Annals cite Conchobhor ua hAinniaraidh, king of Cianachta and Ua Cein king of the Ui Meic Carithinn fell by each other in combat.

By the 12th century, the area of Tirkeeran was divided into three districts, given as belonging to the Ó Eiteagain (O'Ettigans) in the 12th century: Teallach Caghalain; Teallach Duibhailbe; and Teallach Braeain. Prior to the 13th century the septs of Ó Cairealláin (O'Carolan) and Mac Eiteagain (MacEttigan) are cited as ruling the territory of Clann Diarmatta (south-east of Lough Foyle), which contained the present-day parish of Clondermot (which derives its name from the territory). These septs descend from the Cenél nEóghain branch Clann Conchúir Magh Ithe (Clan Connor of Moy Ith), of which the O'Cahans were the principal sept and who would later dominate and rule a territory spanning the baronies of Tirkeeran, Keenaght, and Coleraine.

...
Wikipedia