by Garry Bryant/Garaidh Ó Briain
(This article has many Gaelic names and I have no idea how to pronounce but only a few of them [see end for a very small pronunciation guide], just do your best.)
For over a thousand years, in the various annals and histories of Ireland is the story of the origin of the Dál gCais which has been believed as fact, but appears to be a propaganda story. Dál gCais common ancestor is Toirdelbaig [Turlough] who lived around 650 A.D..
The Traditional Story
The second son of the king of southern half of Ireland whose name is Olliol Olam/Ailill Allamh (d: 234 A.D.), is one Cormac Cas.1 In a poem by Olliol Olam he recounts his nineteen sons by different wives (not to mention daughters), and nine of those sons by Sadb ingen Chuinn, daughter of the High-King Conn 'of the Hundred Battles.' Olioll was Sadb’s second husband.2 A disgruntled Irishman gathered a foreign army and invaded the Emerald Isle. The High-King and his allies joined forces to meet the threat, and Olioll and his sons were among them. The invaders were victorious at the Battle of Magh Muchruime and all but two of Olioll’s sons were slain.
In King Olioll’s will he stated that his kingdom was to be divided among his sons, and that the two eldest were to alter the kingship every other generation. These three sons were the late Eóghan Mór, who was the eldest, and left a son behind named Fiachadh Muilleathan, [p.262] obtained the kingdom of Desmond in southern Munster. The second son was Cormac Cas who inherited the kingdom of Thomond in north Munster, and the youngest son was Cian/Kian who received the kingdom of Ormond in eastern Munster.3 The three ancient gold crowns on a blue field in the arms and flag of the province of Munster represent these kingdoms.4
Eóghan Mór became the progenitor of the Eóghanachts (Eugeneians) who became known as the MacCarthys, who were the senior house. The various branches of the MacCarthys constantly ruled Munster for over five hundred years. The Eóghanachts tribes various septs include O’Sullivan, O’Donoghue, O’Mahony, O'Callaghan, O’Driscoll, etc. The second son was Cormac Cas, progenitor of the Dál gCais (Dalcassians), whose senior house became the O’Brien’s several centuries later, whose septs (clan branches) number about 52 clans. Lastly is Cian, progenitor of the Ciannachts/Elyians, who live in the territory of Éile/Ely in northern Ormond, whose senior house is the O’Carrolls and its septs are O’Meagher, O’Hara, O’Gara, etc.
The Dál gCais tribe’s name literally means "part of Cas," or "descendants of Cas." The Gaelic word ‘dál’ translates to "part of," or "from." Another Gaelic word is ‘corcu,’ which means the same thing as does the ending ‘raige,’ i.e., Corcubisciin and Muscraige, both native tribes of Munster. After the coming of Christianity these words were dropped and the sept names beginning with h/hi/hy, then to Ua as in Ua Neill, were used, later anglicized to O’Neill, and in modern Irish as Ó Neill.
What the Dál gCais had in common was that of ‘blood descent from a common ancestor,’ (discovery of the Irish Type III DNA markers unique to the Dál gCais supports this part of the story. The unique haplo group is designated as 'R:L-226'. This SNP marker is only found in Ireland and mostly in the Thomond area) in their case it was Cormac Cas mac Olioll according to the ‘traditional’ account, and that is probably how it should be remembered and taught, that the origin of the Dalcassians from Cormac Cas is ‘traditional.’
Propagating these traditional stories in his massive genealogical work (published first in 1876, the most quoted being the 1923 version) titled Irish Pedigrees; or the Origin and Stem of the Irish Nation, was John O’Hart. O’Hart strongly believed the traditional accounts of the coming of the Gaels. Today’s scholars are very suspicious of these traditional stories for most were written down by monks during the centuries of six through nine A.D.. The problem is that the original sources used no longer exist to check the facts. The monks included Biblical stories to fit into the Gaelic ones. Several centuries go by and the works are recopied and distributed with the transcribers adding thoughts and ideas of their own. So what is fact and what is myth and legend is unknown, thus the stories are labeled as 'tradition.'
As stated earlier it was the desire of King Olioll Olum to have the kingship of Munster alternate between Desmond (south Munster) and Thomond (north Munster), but for some reason the Dál gCais never exercised this right until the mid 900s. The Eóghanachts were not happy with this development but according to the agreement it was the Dalcassians right. Still, the Eóghanachts to this day consider that the Dál gCais usurped the throne of Munster from the Eóghanachts.
Finding the truth in the myth
Authors and historians Rev. John Ryan (North Munster Antiquarian Journal, 1943) and John V. Kelleher (North Munster Studies, 1967) put this traditional story under the microscope and their theories and conclusions were published in two well known journals.5
The history of the prominent peoples of Ireland began to be recorded in the fifth century, and the name of Dál gCais is not found in any of them. The first time the Dál gCais are found in any records or annals is 934 A.D., in the Annals of Inisfallen, records the death of "Rebachan son of Mothlae, abbot of Tomgraney, and king of Dál Chais (Dál gCais)." Second mention of this tribe of Thomond is found in the annal of the Chronicon Scotorum, and the third was in 951 concerning the death of Cennétig mac Lorcáin, king of Dál gCais, in the Annals of Ulster and Annals of Innisfalen. The Book of Rights mentions them prominently about 1000 A.D. The point here is to show that before 934 the name of Dál gCais was unknown to historians.
So there has to be another name for this tribe of people in north Munster, and that name is ‘In Déisi Tuascrit.’
Coming of the Déisi
The Déisi/Dési lived in the lands of Waterford and southern Tipperary and were called Déisi Muman, having originally been from around Tara in Meath.6 Ancient meaning of the Gaelic word déisi, meant a "people who were vassals," a term that could be applied to a number of
communities.7 It would appear though that the Déisi of Waterford were a very cohesive entity which alludes to the possibility of them having common descent. Author Dáibhí Ó Cróinín puts forth the theory that they were of the prominent Érainn people called the ‘Maritine.’8 The Déisi had a reputation as "nobody’s darlings," and for a couple of centuries driven around Ireland trying to exist. Then came a series of wars between the provinces of Munster and Leinster for the control of "clar machaire na Muman," a plain in the province of Munster. The Déisi sided with the Eóghanachts, and helped in driving the Leinstermen back to the present Tipperary-Kilkenny border. The Eóghanachts offered to the Déisi as a reward, large grants of land in Waterford and south Tipperary, which the tribe extended in time to what would become east Limerick, and into north Tipperary, all by the sword. This northern stretch was very narrow. What the Déisi were was a buffer between the Eóghanachts and the province of Leinster (eastern Ireland).9
Over time the Déisi split into two groups: In Déisi Becc and In Déisi Tuaiscirt.10 Tradition among the Déisi tells of an agreement between the two that the Déisi kingship would alternate every other generation. The Déisi Becc expanded west of Waterford and north into southern Tipperary. The Déisi Tuaiscirt continued the conquest north and entered Limerick slashing and burning their way into southern Connacht and established a border that stands to this day between the province of Connacht and County Clare. This occurred in the period of 350-375 A.D.11 In time this newly acquired territory was called Thomond meaning north Munster.
The king of Thomond was of one tribe/clan or another for generations, but around 650 A.D., a warrior by the name of Toirdelbaig, came to the throne of Thomond. He was the progenitor of Uí Toirdelbaig clan, of whom the Dál gCais descend, and the direct line of descent went down to Brian Boru, and his clan, and the O’Brien’s became the senior house by right of the strong arm. King Tordelbaig’s second son was Flannan who entered the priesthood and became the patron saint of the Dál gCais.
In Déisi Tuaiscirt is mention a few times in the annals and records, yet very little. Not until 934 with the death of abbot Rebechan did a member of Uí Tordelbaig become king again, and that man was Lorcáin (2nd great-grandson of Tordelbaig), who was followed by his son Cennétig who was in the battle of Gort Rottacháin in 944, where two of Cennétig’s sons were slain fighting against the king of Munster, Cellachán mac Buadacháin.12 Cennétig mac Lorcáin spent his entire life fighting against the Norse of Limerick and was killed by them in 951. Cennétig’s son Lachtna, ruled Thomond for three years and died, a younger brother of his, Mathgamain/Mahon, took up the sword and exercised the might of the Dál gCais and wrested the crown of Munster away from the Eóghanacht’s accompanied by his youngest brother Brian.
How can the most insignificant tribe on the Emerald Isle rise up in might in a generation to become one of the most powerful tribes in all Ireland who called themselves the Dál gCais?
For many decades the Eóghanacht’s had been a rival to the Uí Neill’s who occupied Tara and the High-Kingship. Tara could see that the might of the Eóghanacht’s was declining and the Uí Neill’s would dearly love to drive a wedge into the various factions of the Munster tribes. Who would they choose?13
Location, location, location
The Dál gCais territory lay on both sides of the Shannon River, from just north of Limerick to Lough Derg. The Dál gCais controlled the river entrance into the heartland of Ireland. They also
controlled the portages, fords, and rapids of the river. This made it difficult for the Norse and their long-ships to carry on their military and raiding exploits into Ireland. The Uí Neill’s choice was the Dál gCais according to author John Kelleher.14
In 941 A.D., Dalcassian princess Orlaith, the daughter of the King of Thomond, Cennétig mac Lorcáin, was put to death by Donnchad, High-King of Ireland, for sleeping with his son Oengus. Orlaith was one of four wives to the king, a second wife or royal concubine. Author Kelleher points out that this is important for it shows this was a political marriage involving the king of Tara and a petty kingship of the Dál gCais. Obviously he had no concern about a Dál gCais reprisal for Orlaith’s death.15 It was a warning to Orlaith’s kindred to keep in their place, but a couple of decades later the Dál gCais led by Mathgamain were able to continue the struggle in their ascent to kingship by themselves.
Not only did the O’Neill’s of Tara assist the Dál gCais to overthrow their overlords, but the Eóghanacht also helped in a roundabout way for they were a declining power in Munster. The various branches of the Eóghanacht Tribe could not produce a man strong enough to hold together the quarreling factions of Munster. Suddenly in 964 the king of Thomond, Mathgamain mac Cennétig, assembled the Dalcassian army and allies and marched to Cashel where he usurped the throne of Munster away from the Eóghanacht. Mathgamain’s genealogical pedigree wasn’t impressive; the Dál gCais were really Déisi, vassals, not warrior kings. This did not look good neither for the Ui Niell’s or the Eóghanacht's.
It is at this time that there appears a new or revised pedigree showing that the Dál gCais descended from Cormac Cas, son of Oilill Ólum, King of Munster about 190 A.D. This brought them into a cousin relationship with the Eóghanacht, who descended from Eóghan Mór, also a son of Oilill and Cormac Cas’ elder brother.16
Kelleher states that this false pedigree obviously wasn’t an invention of the Eóghanacht, nor was it an invention of the Dál gCais, for they weren’t strong enough in the 900s to make this grafting into the Eóghanacht pedigree stick. The only power resided with the Uí Néill of Tara.17
Faking pedigrees and genealogies was nothing new. As early as 846 A.D., the Uí Néill had used the altering of prehistoric pedigrees as a political weapon. They altered many genealogies of families in north and east Munster to bring them away from dependence on Cashel, to a more semi-independence under the Uí Néill. This changed the Osraige tribe to join the Laigin, and the Déisi (without In Déis Tuaiscirt) were made to descend from a brother of Conn Cetchathach.18
So the account of descent from Olioll Olum by the Dál gCais should not be taken as fact, but remembered as a tradition. What should be remembered is that the Dál gCais Tribe comprises of some 52 clans which all have a common ancestor in Tordelbaig/Toirdealbhaigh, king of Thomond circa 650. That the Dál gCais had the honor of leading the king of Munster’s army into battle, and whose battle flag was of the color "red, purple, gold, & dung," and are known as the kindred of High-King Brian Boru.
Dál gCais - Ó Briain (O'Brien) of Uí Toirdealbhaigh, Mac Conmara (MacNamara), Ó Cinnéide (Kennedy), Ó hEachthianna (Ahern or Hearne), Ó Beolláin (O'Boland), Mac Fhlannchaidh (Mac Clancy), Mac Consaidín (MacConsidine), Mac Cochláin (Mac Coughlan), Ó Fhógartaigh (O'Fogarty), Ó Gradaigh (O'Grady), Mac Domnaill (MacDonnell), Ó hAnrachain (O Hanrahan), Ó hArtagáin (O'Hartigan), Ó hIcidhe (Hickey), Ó hÓgáin (Hogan), Ó Urthaile (O'Hurley), Ó Cearrnaigh (Kearney), Ó Céileachair (Kelleher), Ó Cadhla (Kiely), Mac Mathghamha (MacMahon), Ó Maol- omhnaigh (Moloney, Mullowney or Maloney), Ó Maolchaoine (O'Mulqueen), Ó Neachtain (O'Naghten), Ó Cuinn (O'Quinn), Ó Murruanaidh (O'Moroney), Ó Riagáin (O' Regan or Reagan), Ó Seanachain (O'Shanahan), Ó Siodhachain (Sheehan), Mac Giolla Iasachta (MacLysaght), Ó Gealbhain (O'Galvin), Ó Meadhra (O'Meara, O'Mara), Mag Raith (MacGrath), O'Durack.
Sól Cennétich - baronnies of Upper and Lower Ormond, e.g. Ó Cinnéide (Kennedy)
Muintir Ifernain - O'Quinn of Corofin in the county Clare
Ui Fearmaic - Ó Deaghaidh (O'Dea)
Dál gCais/Dalcassian - the race of Cas: Sixth in descent from Cormac Cas, son of Oilioll Olum, King of Munster in the 3rd century. Through this 'traditional' line they are connected to Cashel and the other great families of the province of Munster. This great clan of Thomond (North Munster: counties Clare, Limerick, north Tipperary), 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 Dál gCais. One of several clan names which apply to the MacNamaras and their co-relatives in Thomond.
Uí Caisin - descendants of Caisin, son of Cas, the name of a branch of the Dál gCais of which MacNamara was chief.
Cineal Cuallachta - the race of Cuallachta or Collachtach; a branch of the Dál gCais or Dalcassians. These families are descended from Aonghus Ceannathrach, son of Cas, and centered in the barony of Inchiquin, County Clare. O'gRiobta was the chief family of this tribe.
Muintear Ifearnain - The family of Ifearnan, a branch of the Dál gCais. This was the clan name of the O'Quinns of Thomond who descend from Ifearnan, son of Corc, the 15th in descent from Cormac Cas, the ancestor of the Dál gCais or Dalcassians.
Uí Bloid - descendants of Blod, son of Cas, a branch of the Dál gCais. This clan includes the O'Kennedy, O'Shanahan, O'Durack and O'Ahern families of eastern County Clare. The name is still preserved in the place name of the deanery of Omulled.
Uí Cearnaigh - descendants of Cearnach, the branch of the Dál gCais of which the Ahernes were chiefs.
Uí Ronghaile - descendants of Ronghal, a branch of the Dál gCais of which the O'Shanahans were chiefs.
Uí Toirdealbhaigh - descendants of Toirdealbhaigh (Father of St. Flannan), King of Thomond. The clan name of the O'Briens and their co-relatives in the east of County Clare.
Uí Cormaic - descendants of Cormac, the clan name of the O'Hehirs in Thomond.
Corca Bhaiscinn - the race of Cairbre Baschaoin, centered in the south-west of County Clare. [Not Dalcassian].
Corca Modhruadh - the race of Modruadh, son of Fergus MacRoigh. This is the name of a 'great clan' in the north-west of County 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 Dalcassian clan. [Source: http://www.irishroots.com/july96.html]
Tuadh Mumhan (nowadays known as Thomond and covering the counties of Clare, Limerick, North Tipperary) become a separate Kingdom within the province of Mumhan (Munster) as the powerful tribe of the Dál gCais rose to power. The most famous member of this tribe being Brian Boru and the first High King of Ireland in reality.
The O’Briens were the ruling family of Tuamumu and other leading families include:
(Mac) Clancy (Mac) Conway (Mac) Corcoran (O) Bannon (O) Boland (O) Cahill (O) Carroll (O) Connor (O) Dea (O) Donovan (O) Dooley (O) Drennan (O) Dwyer (O) Fennessy (O) Flaherty (O) Flanagan (O) Fogarty (O) Galvin (O) Grady (O) Halloran (O) Hannon (O) Heffernan (O) Hehir (O) Hickey (O) Hogan (O) Honan (O) Hurley (O) Kearney (O) Kelleher (O) Kennedy (O) Kiely (O) Loughlin (O) Meagher (O) Melody (O) Mulcahy (O) Naghten (O) Quirke (O) Reddan (O) Regan (O) Reidy (O) Shannon (O) Sheehan Ahern Buckley Collins Curry Flannery Gilroy Gleeson Houlihan Mac Considine Mac Enery Mac Namara MacDonnell MacGrath MacInerney MacMahon Maher Malone Maloney O’Meara Ryan Sexton
[Mike Collins, The Tribes of Ireland – Ireland at the Birth of Your Irish Surname. ]
Some Dál gCais tribe - clan/sept
Clann Chuileainn = MacNamara
Ui Caisin = MacNamara
Cineal Cuallachta = O'gRiobta
Muintear Ifearnain = O'Quinn
Ui Blod = O'Kennedy, O'Shanahan, O'Durack and O'Ahern
Ui Cearnaigh = O'Ahern
Ui Ronghaile = O'Shanahan
Ui Toirdealbhaigh = O'Brien
Ui Cormaic = O'Hehir
Gaelic - English
Déisi/Dési - Day-shee
Dál gCais – Dal-gash
Eóghan – Owen
Mathgamain - Mahon
Cennétig – Kennedy
Donnchad – Donald
Lough – Loch
Magh - Moy
Sadb – Save
Mac – Son of
1 John T. Koch, Celtic Culture: an Historical Encyclopedia. (Santa Barbara, CA: ABC-CLIO, 2006).P.554 ; John O'Dugan, The Kings of the Race of Eibhear. (Gryfons Publishers & Distributors, 1999) P.9.
2 Geoffrey Keating (translator of the original Irish) & Dermod O’Connor, The General History of Ireland, (Dublin: James Duffy, 1841, first published in Irish 1644 & English 1723) P. 261.
3 Keating, p. 263.
5 Rev. John Ryan, S.J., D.Litt. "The Dalcassians," North Munster Antiquarian Journal. Vol. 3, #4; autumn, 1943; John V. Kelleher. "The Rise of the Dál Cais," North Munster Studies. (Limerick: The Thomond Archaeoloical Society, 1967.) Pp. 230-241.
6 "The Mabinogion: The Third Branch," ‘The Expulsion of the Déisi’ - The Mabinogi of Manawydan, p.381.
7 Elizabeth Fitzpatrick, Royal Inauguration in Gaelic Ireland c. 1100-1600. (Boydell Press, 2004) P.36.
8 Dáibhí Ó Cróinín (ed.), "Ireland, 400-800", A New History of Ireland: Prehistoric and Early Ireland. Volume 1. (Oxford University Press, 2005) P. 222.
9 Ciaran O Murchadha, "The Dál gCais (Dalcassians) and the Territory of Tuamhumhain (Thomond)," The Royal O’Briens: A Tribute. (Ireland: O’Brien Clan Association, 1992) P.6.
10 Fitzpatrick, p.36.
11 Murchadha, p.6.
12 Benjamin T. Hudson, "Cellachán mac Buadacháin (d. 954)", Oxford Dictionary of National Biography, (Oxford: Oxford University Press, 2004).
13 Kelleher, pp. 230-241.
14 Kelleher, pp.230-241.
15 Kelleher, pp.230-241.
16 Kelleher, pp.230-241.
17 Kelleher, pp.230-241.
18 Kelleher, pp.230-241.
My name is Garry Eugene Bryant, or in Irish, Garaidh Eóghan Ó Briain. My O'Bryan family emigrated from Ireland to Canada around 1830. They were devout Catholics and my 2nd great-grandfather, William, was informed by his parents that he was to become a priest like his two older bro-thers. He ran away changed his name by dropping the O' and adding a 't,' and ended up at Black Hawk, Col-orado about 1861. But this story was family tradition, no paper doc-ument to that gives the name change. To the rescue came Family Tree DNA and the O'Brien Surname Project which confirmed that I was not only of the Dál gCais Tribe with the R-L226 & FGC5659 snp marker's, but a distant cousin to Sir Conor M. E. O'Brien, Chief of the O'Brien Clan. So I'm not an English Bryant, but an Irish O'Brien! I have three children, all grown and married, and two grandchildren. I'm a retired photojournalist, am passionate about family history and heraldry.