From Irish Pedigrees; or the Origin and Stem of the Irish Nation by John O'Hart
THE chiefs and clans of Tir-Owen, and the territories they possessed in the twelfth century, as given by O'Dugan, are as follows:—
1. O'Neill and MacLoghlin, as princes.
2. O'Cahan, of the race of Owen, and who was chief of Cianacht of Glean Geibhin (or Keenaght of Glengiven). The O'Cahans were also chiefs of the Creeve, now the barony of Coleraine; and in after times, possessed the greater part of the county Derry, which was called "O'Cahan's Country;" they also, at an early period, possessed part of Antrim, and had their seat at the castle of Dunseverick.
3. The O'Connors, who were chiefs of Cianacta before the O'Cahans, and were descendants of Cian, son of Olioll Olum, King of Munster: hence their territory obtained the name of Cianachta, a name still preserved in the barony of ''Keenaught," county Derry.
4. O'Duibhdiorma or O'Dwyorma, sometimes anglicised O'Dermot or O'Dermody, but a distinct clan from MacDermot, prince of Moylurg, in Connaught. The O'Dwyorma were chiefs of Breadach which comprised the parishes of Upper and Lower Moville, in the barony of Innishowen. The name of this district is still preserved in the small river "Bredagh," which falls into Lough Foyle.
5. O'Gormley or Grimly, chief of Cineal Moain, now the barony of Raphoe, county Donegal.
6. Moy Ith and Cineal Enda, partly in the barony of Raphoe, and partly in the barony of Tirkeran in Derry. O'Flaherty places Moy Ith in Cinachta or Keenaught. According to O'Dugan, the following were the chiefs of Moy Ith:—O'Boyle, O'Mulbraisil, O'Quinn, and O'Kenny.
7. O'Broder, O'Mulhalland O'Hogan, chiefs of Carruic Bachuighe, still traceable by the name "Carrickbrack," in the barony of Inishowen.
8. O'Hagan, chief of Tullaghoge in the parish of Desertcreight, barony of Dungannon, and county Tyrone.
9. O'Donegan or Dongan, MacMurchadh or MacMorough, O'Farrell or Freel, and MacRory or MacRogers, chiefs of Tealach Ainbith and of Muintir Birn, districts in the baronies of Dungannon and Strabane.
10. O'Kelly, chief of Cineal Eachaidh or Corca Eachaidh, probably "Corcaghee," in the barony of Dungannon.
11. O'Tierney, and O'Kieran chiefs of Fearnmuigh.
12. O'Duvany, Oh-Aghmaill or O'Hamil, and O'Heitigen or Magettigan, chief of three districts called Teallach Cathalain, Tealach Duibhrailbe, and Tealach Braenain.
13. O'Mulfoharty, and O'Heodhasa or O'Hosey, chiefs of Cineal Tighearnaigh.
14. O'Cooney, and O'Bailey (Bayly, or Bailie), chiefs of Clan Fergus.
15. O'Murchada, O'Murphy, and O'Mellon, chiefs of Soil Aodha-Eanaigh.
16. MacFetridge, chief of Cineal Feraidaigh, in the north of Tyrone. In the Annals of the Four Masters, under A.D. 1185, mention is made of Gillchreest MacCathmhaoil (MacCampbell or MacCowell), head chieftain of the Cineal Fereadaidh, who was slain by O'Negnaidh or O'Neney, aided by Muintir Chaonain or the O'Keenans. That Gillchreest MacCathmhaoil, was also head chieftain of clan Aongus, clan Dubhinreacht, clan Fogarty O'Ceannfhoda, and clan Colla of Fermanagh—"the chief of the councils of the north of Ireland." These Cathmhaoils were a powerful clan in Tyrone, and many of them in Monaghan, Louth and Armagh.
18. The clans of Maolgeimridh (Mulgemery, or Montgomery) and of Maolpadraig or Kilpatrick, who possessed the two districts of Cineal Fereadaidh (or Faraday), in the east of Tyrone.
19. Muintir Taithligh of Hy-Laoghaire of Lough Lir, a name anglicised MacTully or Tully.
20. O'Hanter or Hunter, chiefs of Hy-Seaain.
The following chiefs and clans, not given by O'Dugan, are collected in Connellan's Four Masters, from various other sources:
1. O'Criochain or O'Crehan (mentioned in the Annals of the Four Masters, under A.D. 1200), chief of Hy-Fiachra, a territory which comprised the parish of Ardstraw, and some adjoining districts in Tyrone.
2. O'Quinn, chief of Moy Lugad and of Siol Cathusaigh (a quo Casey), as given by the Four Masters, under A.D. 1218. Moy Lugad, according to the Books of Lecan and Ballymote, lay in Keenaght of Glengiven, county Derry.
3. The O'Cearbhallins (O'Carolans, or Kerlins), a name sometimes anglicised "Carleton," were chiefs of clan Diarmaida, now the parish of Clandermod or Glendermod, in Derry.
4. The O'Brolachans, by some changed to Bradley, etc., were a branch of the Cineal Owen.
5. MacBlosgaidh or MacClosky. a branch of the O'Cahans, was a numerous clan in the parish of Dungiven and the adjoining localities.
6. O'Devlins, chief of Muintir Dubhlin, near Lough Neagh, on the borders of Derry and Tyrone.
7. The O'Looneys, chiefs of Muintir Loney, a district known as the Monter Loney Mountains in Tyrone.
8. O'Connellan, chief of Crioch Tullach in Tyrone.
9. O'Donnelly, chiefs in Tyrone, at Ballydonnelly and other parts.
10. O'Nena (ean: Irish, a bird), O'Neny or MacNeny were chiefs of Cineal Naena, in Tyrone, bordering on Monaghan; of this family was Count O'Neny of Brussels, in the Austrian service, under the Empress Maria Theresa.
11. O'Flaherty, lord of Cineal Owen, but a branch of the great family of O'Flaherty in Connaught.
12. O'Murray, a clan in Derry.
13. MacShane (a name anglicised "Johnson"), a clan in Tyrone.
14. O'Mulligan, anglicised "Molineux," were also a clan in Tyrone.
15. O'Gnive or O'Gneeve (anglicised "Agnew") were hereditary bards to the O'Neills.
The O'Neills maintained their independence down to the end of the sixteenth century, as princes of Tyrone; and in the reigns of Henry the Eighth and Elizabeth, bore the titles of Earls of Tyrone and barons of Dungannon. The last celebrated chiefs of the name were Hugh O'Neill, the great Earl of Tyrone, famous as the commander of the northern Irish in their wars with Elizabeth; and Owen Roe O'Neill, the general of the Irish of Ulster in the Cromwellian wars, A.D. 1641. Several of the O'Neills have been distinguished in the military service of Spain, France, and Austria. In consequence of the adherence of the Ulster chiefs to Hugh O'Neill, in the wars with Elizabeth, six counties in Ulster were confiscated, namely: Tyrone, Derry, Donegal, Fermanagh, Cavan, Armagh—all in the reign of King James the First. A project was then formed of peopling these counties with British colonies; and this project was called the "Plantation of Ulster."
 Tirowen: After the conquest of Ulster by the three Collas, this territory was comprised within the Kingdom of Orgiall; but Niall of Ihe Nine Hostages, the 126th Monarch of Ireland, conquered that part of it called the "Kingdom of Aileach," of part of which (Tirowen) his son Eoghan or Owen, and of the other part (Tirconnell), his other son, Conall Gulban, were the first princes of the Hy-Niall sept. In after ages the territory of Tirowen expanded by conquest, so as to comprise the present counties of Tyrone and Derry, the peninsula of Inishowen (situate between Lough Foyle and Lough Swilly), and the greater part of the barony of Raphoe, in the county Donegal. This ancient territory is connected with some of the earliest events in Irish history. The lake now called Lough Foyle, according to Keating and O'Flaherty, suddenly burst forth in the reign of the Monarch Tiernmas, No. 41, page 354, and overflowed the adjoining plain, which was called Magh Fuinsidhe. This lake, mentioned in the Annals of the Four Masters as Loch Feabhail Mic Lodain, obtained its name from Feabhail (or Foyle), son of Lodan, one of the Tua-de-Danan chiefs, who was drowned in its waves. In this territory, on a high hill or mountain called Grianan, on the eastern shore of Lough Swilly, south of Inch Island, was situated the celebrated fortress called the Grianan of Aileach (from "Grianan," a palace or royal residence, and "Aileach" or "Oileach," which signifies a stone fortress), This fortress was also called "Aileach Neid" or "Oileach Neid," from Neid, one of the Tua-de-Danan princes; and was for many ages the seat of the ancient Kings of Ulster. It was built in a circular form of great stones without cement, of immense strength, in that style called "Cyclopean" architecture; and some of its extensive ruins remain to this day. It was demolished, A.D. 1101, by Murtogh O'Brien, King of Munster and the 180th Monarch of Ireland. This palace of Aileach is supposed to have been the "Regia" of Ptolemy, the celebrated Greek geogragher, in the second century; and the river marked "Argita" on his map of Ireland, is considered to have been the Finn, which is the chief branch of the Foyle river. The territory surrounding the fortress of Aileach obtained the name of Moy Aileach or the Plain of Ely. Tirowen was peopled by the race of Owen or the Clan Owen, some of whom, on the introduction of sirnames, took the name of "O'Neill," from their ancestor Niall Glundubh, the 170th Monarch of Ireland; and some of them, the name MacLoghlin, from Lochlan, one of the Kings of Aileach. Some of the MacLoghlins, during the eleventh and twelfth centuries, were princes of Tirowen, and some of them were Monarchs of Ireland. Altogether, according to O'Flaherty, sixteen of the Clan Owen were Monarchs of Ireland.