The Erdini, according to some authorities, were the inhabitants of this district FERMANAGH in the time of Ptolemy; but Whitaker considers it to have been part of the Nagnatae. By the ancient Irish it was called Feor Magh Eanagh, or "the Country of the Lakes," and Magh Uire, or "the Country of the Waters:" it was also called Ernai or Ernagh, and the inhabitants who lived around Logh Erne, Ernains and Erenochs. a name supposed to be derived from the Erdini. It was divided into two great portions, one called Targoll, the ancient seate of the Facmonii, and of the Macmanii, or the Mac Manuses; the other named Rosgoll, occupied by the Guarii or Guirii, from whom the Mac Guires, or Maguires, derive their origin. This family was so powerful that the greater part of the county was for several centuries known by the name of Mac Guires country.

In County Fermanagh. According to one story, the original 'Fir Manach' are claimed to come from Leinster, reaching the Upper Lough Erne at very early date. "At the coming of Christianity, Fermanagh was partly independent (i.e. original tribes), partly under the Oriel tribes and partly under Connaught influence." (Livingstone 1969, 6).

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The Airghialla federation included Uí Cremthainn, Uí Méith, Uí Tuirtre, Uí Meic Uais, Uí Fiachra Ard Sratha, Mughdorna, Uí Meic Cáirthinn, Airthir, Fernmhaighe, and Fir Lí, among other terms descriptive of tribal groupings and territories. In addition, other places where Arghialla groups have been noted included areas within the modern counties of Tyrone, Cavan, Meath, Westmeath, Louth, and Derry. Their territory, depending on timeframe, included much of what includes the modern counties of Monaghan, Armagh and Fermanagh.

Throughout the 11th and 12th centuries the Kings of Fermanagh - O'hEignigh, O'Maolruanaidh and O'Dubhdara - were drawn from the Airghialla [Oriel], its Clann Lugainn branch, which is stated in the early genealogies to descend from one of the three Collas, i.e. Colla Fochríth. The O'Heany or Hegney (Ó hEignigh) and Mulrooney (Maolruanaidh) septs were noted as kings of Fermanagh (Fer Manach) until becoming tributary to the Maguires (Meicc h-Uidir) by the 13th century. An early genealogy

 

Fernmag Located in southeast Co. Monaghan. The O'Carrolls are cited as overlords of Oriel in this area. O'Lorcan (Larkin) are cited in the annals as early chiefs of Fernmhaighe (Farney). O'Kieran (Ó Ciaráin) is given as a chief of Fearnmuigh by the writer O'Dugan as a clan of Tir Eoghan. O'Creehan (O'Criochan) appear in the annals as chiefs. MacMahon (MacMathghamhna) were noted as chiefs here in the 13th century. The early genealogy of the Fernmaigi goes back to one of the three Collas, i.e. Colla Fochríth.

Clann Fermaighe - (Glenfarne) Located in northern County Leitrim, south of Dartry, in the present barony of Dromahaire (e.g. Ballinaglera parish). The sept of MacCogadhain or Mac Acadhain (Mac Cogan) were noted as early chiefs in this area. According to the Book of Fenagh, they were a branch of Conmaicni Réin comprising C. Cellachain, C. Maelsamhna, C. Taebhachain, C. Ubhan, C. Lughann, and C. Uanan. They claim descendancy from the first wife of Findellach, the son of Neidhe, and 5th in descent from Cumscrach. Fernmag, or Fernmaighe An early genealogy

A steady push by the Cenél nEógain in the 7th and 8th centuries reduced the size of the Airghiallan federation as the people of northern Airghialla came to be treated as sub-kingdoms of the Cenél nEógain. During a similar period the southern branches of the Airghialla came under the dominion of the southern Uí Néill kingdoms of Mide and Brega. By the 9th century Airgialla proper, as a political entity, was practically confined to the modern counties Armagh, Monaghan, Fermanagh, and part of Louth, with the Uí Thuirtri kingdom in east Tyrone in process of being absorbed into the Cenél nEógain over-kingdom of Ailech.

The Book of Fenagh states the sub-territories of Airgialla were:

Noted chiefs of Airghialla included Ua Laidhgnén (O'Leighnin?), Ua Éiccnigh (O'Heany or Hegney), Ua Cerbhaill (O'Carroll), Ua Baígelláin (O'Boylan), Ua Anluain (O'Hanlon), Mac Mathgamna (MacMahon), among others.

Uí Cremthainn - the territory of Bréifne about eastern Co. Fermanagh and northern Co. Monaghan. The early genealogies state the Uí Chremthaind were descendants of one of the three Collas, i.e. Colla Fochríth. An early genealogy shows descent from Crimthann liath (from whom Uí Crimthainn), son of Fiac, a son of Deach Dorn, son of Rochad, son of Colla da Crich (aka Colla Fochríth). In effect, the Uí Cremthainn consisted of multiple groups, and were considered part of the overall Airghialla confederation. Some of the prominent descendants from Crimthann liath included, among others, the Clann Nadsluaig of modern co. Monaghan (O'Carroll, McMahon, ...), the Clann Lugain of co. Fermanagh (Maguire, McManus, ...), the Clann Ceallaigh (MacDonnell, ...) of co. Monaghan, and the Síl nDamine of co. Fermanagh (Mael Ruanaigh, ...). Each of these were descended through Cairpre Dam Argait, a grandson of Crimthann liath.

Three of the sons of Cairpre:

Cormac (a quo clann Cormaic, clann Lugain, Muintir Pheodachain, Muintir Caeman, clann Fergaile)

Daimine (a quo Síl nDamine, Síl Tuathail an Tuaiscirt, clann Cellaig, Mac Maolruanaig, et al)

Nadsluag (a quo clann Nadsluaig, Ua Cearbhaill, Ua Mathgamna, et al). From clann Lugain the prominent families of Ua hÉicnigh, Mag Uidhir and Mac Maghnuis are noted, among others.

In the late 10th and early 11th centuries the sept of Mael Ruanaigh are noted in the annals as kings of Cremthainn, although this appears to be a reference to the district of Cremthann in Connacht. The MacMurchadha family were prominent as lords of Truagh in northern Monaghan in the barony of Trough, before being overshadowed by the MacKenna(n) sept, of the southern Uí Neill. Included among the prominent Aighialla families were the Ua Baigeallain (O Boylan) of Síl Maeluidir in the area of Dartraige (Darty, western co. Monaghan).

In the 12th century the Ua Cearbhaill (O'Carroll) were prominent among the kings of Arghialla. By the 13th century the family of MacMahon (MacMathghamhna) held the superior authority with the title king of Oirghialla (Oriel), by that time a much reduced sub-kingdom.

According to Ptolemy, this tract, CAVAN, with the districts included in the adjacent counties of Leitrim and Fermanagh, was occupied by the Erdini, designated in the Irish language Ernaigh, traces of which name are yet preserved in that of Lough Erne and the river Erne, upon which and their tributaries these districts border. This district, exclusively of the greater part of the present county of Fermanagh, formed also the ancient principality of Breghne, Brefine, Breifne, Breffny, as it has been variously spelt, which had recognized limits from time immemorial, and was divided into the two principalities of Upper or East Breifne and Lower or West Breifne, the former composed almost entirely of the present county of Cavan, and the latter that of Leitrim.

East Breifne was often called Breifne O'Reilly, from its princes or chiefs having from remote ages borne that name: they were tributary to the O'Nial of Tirowen long before the arrival of the English, although Camden says that in his time they represented themselves as descended from the English family of Ridley, but were entirely Irish in manners. The county is celebrated in the history of the wars in Ireland for the fastnesses formed by its woods, lakes, and bogs, which long secured the independence of its native possessors. When the county was partitioned into its seven baronies, five went to members of the O'Reilly sept, and the other two, more remotely situated in the mountains and on the border of O'Rourke's country (Leitrim), were possessed by the septs of MacKernon and MacGauran.

SLIGO county was included in the territory of the Nagnatae in the time of Ptolemy, the chief city of which tribe, Nagnata, is supposed by some to have been somewhere near the site of the town of Sligo. It was afterwards possessed by a branch of the O'Conors, called for the sake of distinction O'Conor Sligo. The families of O'Hara, O'Dowd, Mac Donagh, and Mac Ferbis, were also heads of septs in different districts. After the landing of the English under Henry II, it gradually fell, together with the rest of Connaught, into the hands of the great English leaders, of whom the De Burgos were the most powerful in these parts. The county was regarded as part of Connaught with the exception of Roscommon, was then considered by the English as a single county, until the 11th of Elizabeth, when the province was divided into seven counties, of which Sligo was made one.

Bréifne (or Breffny, Brefnie, Brenny, ...) was held by the clans of the Uí Briúin Breifne, descendants of Aodh Fionn, from the 7th century up to the mid 17th century. At its maximum extent Bréifne extended from Kells in Meath to Drumcliff in Co. Sligo and was part of the Kingdom of Connacht until the time of Queen Elizabeth I (1565), when it was split into the Counties Cavan and Leitrim. The O'Rourke's (Ó Ruairc) were early Kings of Bréifne, and later Princes of West Bréifne, an area which corresponds roughly to present day County Leitrim. The O'Reilly's (Ó Raghallaigh) were early Lords of East Bréifne, or Muinter Maoil Mordha, an area which was centered in present day County Cavan, a county which became part of Ulster by the 16th century.

Uí Briúin - Co. Roscommon. The early genealogies for the show Brion, son of Eochuid Mugmedón, as the progenitor of many of the royal families of Connacht. Noted chiefs of the Uí Briúin in Roscommon included O'Connor of the Uí Briúin Ai. Clan Mulrooney and Clan MacDermot were noted chiefs in Roscommon.

The Uí Cremthainn of Co. Fermanagh and northern Co. Monaghan. The early genealogies state that the Úi Chremthaind were ancestors of one of the Three Collas, i.e. Colla Fochríth. In the 13th century the family of MacMahon (MacMathghamhna) held the superior authority here with the title king of Oirghialla (Ulster.)

 

About the 13th century O'Dugan, in his Topograhical Poems, makes note of the following families in the Breifne region:

Located in northwestern Co. Leitrim, and part co. Sligo. The early genealogies cite the son of Dáire Sírchréchtach, that is Lugaid Cál "a quo Callraige". The chiefs of Calraighe included O'Finn and O'Carroll (O Cearbhaill). There were also prominent chiefs of Calraige in the west of County Westmeath and north Offaly named Mac Amhalghaidh (MacAwley).

  • For 787, Cathmugh, lord of Calraighe, died.
  • For 1045, Amalgaidh mac Flaind, rí Callraighe.
  • For 1052, Mac Airechtaigh, righ Callraighi.
  • For 1056, Odhar mac Flaind, rí Callraighe.
  • For 1081, Giolla Siadnata mac Amhalghadha, mic Flainn, tigherna Calraighe.
  • For 1103 & 1107, Cionaodh, mac Mic Amhalghadha as lord of Calraighe.
  • For 1105, Niall mac Mic Riabhaigh, tigherna Callraighe died.
  • For 1144, Cionaedh, mac Mic Amhalgadha, toiseach Calraighe, was slain by Flann Mac Amhalghadha.
  • For 1208, Auliffe O'Rothlain, Chief of Calry of Coolcarney, was slain by O'Moran.
  • For 1251, Flaithbertach h. Cerbaill as taisech of Calraige.

Located in western Co. Fermanagh, the Fir Manach, the Cinéal Eanna and the Cenél Láegaire were early indigenous tribes in the Co. Fermanagh area. Various references to Cenél Láegaire septs include: