Early Irish Tribal Origins - an exerpt taken from :
"Ireland History - Early Irish Tribes, Septs and Clans"

by D.W.Walsh, Kilkenny ; full site can be viewed at,

(contains full doument and further references to Irish/English Surname List, Irish History in Maps, Surnames of Clan Cian and The Kings of Leinster and Osraige

Page Index:
Fomorians | Firbolgs | Tuatha De Danann | Laigain | Dal gCais | Eoghanacht | Decies | Desmond

The Myth:
"The tribe of the Fomorians was on the scene long before any other races came to Ireland.
However, the Fomors lived mainly in the sea. The first outside race to invade Ireland was the race of the Partholon; very little is known of them. After 300 years of struggle against the Fomors, the Partholons died of an epidemic.
Next came the race of Nemed who also suffered from an epidemic. This time, though, some of them survived, only to be oppressed by the Fomors.
Later came colonizers from Spain or Greece called the Fir Bolgs. They were actually three tribes; men of Domnu, men of Gaillion, and men of Bolg. They inter-married with the Fomors and held the country until the arrival of the Tuatha De Danann".
Source: (from Ancient and Shining Ones - by DJ Conway)

Firbolgs - Ui Failge, Ui Bairrche, Ui Enachglais, etc. -
The Euerni and later called Erainn (also known as Menapii, Bolgi, Belgae and Firbolgs) by annalists and historians, arrived after ???? BC. They called their new home Eueriio, which would later evolve through the old Irish Eriu to Eire, and from Eire to Ireland.
The early annalists tell us that Firbolg people survived as distinct tribes well into early historical times. In Leinster, they were the Ui Failige, Ui Bairrche and Ui Enechglaiss to mention but a few.
Source: http://www.thecore.com/let-ros/plavin/lavin.html

Tuatha De Danann The De Danann people arrived after the Firbolgs, and were to force the Firbolgs into partial serfdom. The Tuatha De Danann established Tara on the Boyne Valley, the ritual inaugaration and burial place for the ancient Kings of Ireland.
Source: various
In a famed battle at Southern Moytura (on the Mayo-Galway border) it was that the Tuatha De Danann met and overthrew the Firbolgs. The Firbolgs noted King, Eochaid was slain in this great battle, but the De Danan King, Nuada, had his hand cut off by a great warrior of the Firbolgs named Sreng. The battle raged for four days. So bravely had the Firbolgs fought, and so sorely exhausted the De Dannann, that the latter, to end the battle, gladly left to the Firbolgs, that quarter of the Island wherein they fought, the province now called Connaught. And the bloody contest was over.
Source: http://www.vretail.com/history.htm

The Laginian colonization is believed to have taken place sometime about 300 B.C., and are believed to have come from the northwestern region of Gaul, later Normandy. They are mythologically referred to as the Tuatha De Danann. Their name association with Laighi, the ancient name for Leinster, suggests that this was where they first settled. Eventually, they extended their power to Connacht, and in the process forced the Firbolg tribes into the remoter parts of the province. The remains of many great stone forts built by the Firbolgs in their defense against the Laigain tribes can still be seen in remote areas of western Ireland. Within a few generations the Laigain tribes had established themselves in Connacht, where in County Sligo their descendants include the O'Haras, O'Garas, and others.
Source: http://www.thecore.com/let-ros/plavin/lavin.html The ancient Laigin or Dumnonii group moved from the western region of Normandy as the Roman built up pressure on Gaul about 100 B.C. The Laigin settled first in southern Britain and then in Ireland. The Ui Neachtain (Naughton) are said to belong to the Laigain group, later living in the territory of the Ui Maine.
Source: http://miso.wwa.com/~naughton/nau_hist/naughton.html

The Milesians King Milesius and his sons are said to have come from either Spain or France to the island of Ireland, and were ancestors of the Gaels. Of the Milesians, who invaded the Tuatha De Danann lands, Eber and Eremon divided the land between them - Eremon getting the Northern half of the Island, and Eber the Southern. The Northeastern corner was accorded to the children of their lost brother, Ir, and the Southwestern corner to their cousin Lughaid, the son of Ith.
Source: http://www.vretail.com/history.htm
The descendants of Milesius are said to be the monarchs and leading families of early Ireland.

Ui Bairrche
The Ui Bairche (Hy Bairrche) was the generic name for the O'Gormans and related families. The Ui Bairche ruled the tuath or territory of now known as the barony of Slievmargy in Southeast Queens County (Southeast County Leix) adjoining Carlow. An early king of Leinster (Laigin) was Móenach macMuiredach Sníthe O'Bairrche, King of Leinster
Source: http://www.cois.on.ca/~epix/index2.html

Dal gCais
(Dalcassion) the race of Cas, the sixth in descent from Cormac Cas, son of Oilioll Olum, King of Munster in the 3rd century. Through this line they are connected to Cashel and the other great families of the province of Munster. This great clan of Thomond (North Munster), holds several distinguished families including the chief family of the name, the O'Briens. The clan of the noted high king, Brian Boru.
Clann Chuileainn - the race of Cuilean, another branch of the Dal gCais. One of several clan names which apply to the MacNamaras and their co-relatives in Thomand.
Ui Caisin - descendants of Caisin, son of Cas, the name of a branch of the Dal gCais of which MacNamara was chief.
Cineal Cuallachta - the race of Cuallachta or Collachtach; a branch of the Dal gCais or Dalcassions. These families are descended from Aonghus Ceannathrach, son of Cas, and centered in the barony of Inchiquin, Co. Clare. O'gRiobta was the chief family of this tribe.
Muintear Ifearnain - The family of Ifearnan, a branch of the Dal gCais. This was the clan name of the O'Quinns of Thomand who descend from Ifearnan, son of Corc, the 15th in descent from Cormac Cas, the ancestor of the Dal gCas or Dalcassions.
Ui Bloid - descendants of Blod, son of Cas, a branch of the Dal gCais. This clan includes the O'Kennedy, O'Shanahan, O'Durack and O'Ahern families of eastern Co. Clare. The name is still preserved in the place name of the deanery of Omulled.
Ui Cearnaigh - descendants of Cearnach, the branch of the Dal gCais of which the Ahernes were chiefs.
Ui Ronghaile - descendants of Ronghal, a branch of the Dal gCais of which the O'Shanahans were chiefs.
Ui Toirdealbhaigh - descendants of Toirdealbach (Father of St. Flannan), King of Thomand. The clan name of the O'Briens and their co-relatives in the east of Co. Clare.
Corca Bhaiscinn - the race of Cairbre Baschaoin, centered in the south-west of Co. Clare.
Corca Modhruadh - the race of Modruadh, son of Fergus MacRoigh. This is the name of a 'great clan' in the north-west of Co. Clare. Their territory was co-extensive with the Diocese of Kilfenora. The chief families of this clan were the O'Loughlins and the O'Connors. They were not a Dalcassion clan.
Ui Cormaic - descendants of Cormac, the clan name of the O'Hehirs in Thomond.
Source: http://www.irishroots.com/july96.html

The descendants of Eoghan Mór, son of Aillil Olumm (Oilill Olum).
The Eóghanacht Dynasties include the septs of the Eóghanacht Locha Lein, Eóghanacht Maige, Eóghanacht Raithlind, Eóghanacht Airthir Chliach, Eóghanacht Glendamnach, Eóghanacht Chaisil, Eóghanacht Aine, Ui Fidgeinti, Ui Liathain, Ui Maic, Ui Echach Muman, Ui Corpri
Sources: http://acad.smumn.edu/uasal/gencharts/chart01.gif
Oilill Olum became King of Munster and, as head of both the Eberian and Ithian tribes he became the first true King of the whole province. Thereafter the Kingship of Munster was handed down in Oilill Olum's family. Oilill willed, and his will was observed for many centuries, that the crown of Munster should henceforth alternate between the descendants of his two eldest sons, Eogan Mor and Cormac Cas. The MacCarthys are descended from Eogan Mor and the O'Briens are descended from Cormac Cas. The O'Carrolls are descended from Oilill Olum's youngest son Ciann and his son Taig.
Source: http://www.holy.demon.co.uk/chapt01.htm
The MacCarthys, the O'Sullivans and the O'Callaghans, all of Eoghanacht Caisil stock, migrated southwards into Counties Cork and Kerry in pre-Norman times, ousted from their original lands in Counties Tipperary and Limerick by the aggression of the Dál Cais. From longer established tribal groupings in County Cork, such as the Corca Laidhe, the Muscraighe and the Eoghanachts of the Cork region, emerged such family names as O'Driscoll, O'Leary, Cronin; Murphy; O'Mahony and O'Keeffe, respectively.
Source: http://homepages.iol.ie/~irishrts/CorkNames.html
The Eoghanachta ruling families were the O'Mahony's and the O'Donoghues. Other names have descended in the form of Spillane, O'Neill, Long, Flynn, Keating, Ring, Canty, Mehigan, Dillon, Healy, Slattery, Coghlan, Cahalane, Canniffe, Heenigan, Flahive, Hurley, Wholey, Kearney, etc.
Source: http://www.clon.ie/text/system/clehis1.html

Native Gaelic peoples called the Deisi, who were driven from Tara, conquered and settled in the area now known as Co. Waterford. Originally referred to as Deise Muman, the area between the River Blackwater and the River Suir is still today called "The Decies".
Waterford city, of Norse foundation and an important port and centre of trade, was a bridgehead for the Anglo-Normans in the 12th century. The eastern part of the county came under the control of the Le Poers, or Powers, family, and the western part, called the Decies, came under a branch of the Fitzgeralds. The native Irish character of the population was never wholly obliterated; and in the west, near Dungarvan, Gaelic continued to be spoken into the 20th century.
Source: various

Desmond was an ancient territorial division of Ireland approximating the modern counties of Kerry and Cork. Gaelic Desmond extended over the modern County Kerry south of the River Maine and over the modern County Cork west and north of the city of Cork. Early peoples of the area included the Erainn, Corca Duibhne, Corca Loigde, Ui Fidgente, Obraigne, Ciarraige Luachra, and septs of the Eoganachta.
Anglo-Norman Desmond extended over north Kerry from the River Maine, over most of the modern county of Limerick, southwest Tipperary, east and south County Cork, and east Waterford.
Desmond was MacCarthy territory from as early as A.D. 150. In 1329 Maurice Fitzgerald was created earl of Desmond, and his descendants became almost independent rulers during the 15th century.
Source: various

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