| Tirkeeran | |
| Native Name: | Irish: Tír Mhic Caoirthinn |
| Subdivision Type: | Sovereign state |
| Subdivision Name: | United Kingdom |
| Subdivision Type1: | Country |
| Subdivision Name1: | Northern Ireland |
| Subdivision Type2: | County |
| Subdivision Name2: | Londonderry |
Tirkeeran 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; and Strabane Upper to the south.
Tirkeeran derives its name from the territory of the Airgiallan clan Irish: Ui Mhic Carthainn (MacCarthain), one of the earliest tribes in the area based to the south-east of Irish: Locha Febail (Lough Foyle). The Irish: Uí 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 Irish: Uí Meic Cairthinn in 677, when he was killed by the Irish: [[Cenél nEógain|Cenél nEóghain]] king, Mael Fithrich. It was around this period that the Irish: Cenél nEóghain were attempting to expand eastwards from their homeland in Innishowen, in modern-day County Donegal and into central Ulster. Eventually, the Irish: Cenél nEóghain crushed the power and independence of the Irish: Uí Mhic Carthainn and subjugated them; however, it would remain in some minor form until the end of the 11th century, when the Annals cite "Irish: italic=unset|Conchobhor ua hAinniaraidh, king of Irish: italic=unset|Cianachta and Irish: italic=unset|Ua Cein king of the Irish: italic=unset|Ui Meic Carithinn fell by each other in combat".
Prior to the 13th century the septs of Irish: Ó Cairealláin (O'Carolan) and Irish: 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 Irish: Cenél nEóghain branch Irish: 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.
When the baronies of Ulster were being created by the English from 1585, the general manner was to name it after the principal town or castle lying within the area, in which they held their court, baron, and jail. This resulted in Firnacreeve being renamed as the barony of Coleraine, and Kinel-Ferady to the barony of Clogher. The 1591 inquisition which shired County Tyrone specified as one of its eight baronies "Anagh, conteyninge [containing] Tyrchyrine [Tirkeeran], Sgryn [Magilligan], and Clandermod [Clondermot]".[1] The name Anagh was after the O'Cahans' castle, which stood on an island in Enagh Lough. Anagh was one of three baronies transferred from Tyrone to the new County Coleraine, which in turn was enlarged and renamed County Londonderry in 1613. The name of the barony was changed from Anagh to Tirkeeran some time between 1615 and 1639.
Below is a list of settlements in Tirkeeran:
Below is a list of civil parishes in Tirkeeran: