Septs and kindreds The septs of the Dál gCais developed over time, with new ones breaking off to form separate surnames at different times, but all claiming to share the same paternal line (with a few biological exceptions along the way due to adoption or extra-marital issue). Their eponymous founder Cas had several sons; two of them gave their names to the
Uí Bloid and
Uí Caisin kindreds, and another founded the
Ui Fearmaic. As the proto-Dál gCais moved up into what is today
East Clare, these became associated with rooted tribal areas, but were themselves internally divided into any other septs. , in
Corcomroe Abbey, where he was buried by the monks after he and his men were killed by Conor Carrach O'Loughlin The senior line descended from Cas' first son Bloid and they provided the
Kings of Thomond. Initially, the leaders of the tribe were a sept known as the
Uí Aengusa from which descends
O'Curry,
O'Cormacan and
O'Seasnain. However, during the 10th century, this passed to the junior
Uí Thairdelbaig. It is this kindred which would furnish the
High Kings of Ireland and the
Kings of Thomond including Brian Bóruma. From the
Uí Thairdelbaig came
O'Brien,
O'Kennedy (who were
Kings of Ormond),
MacConsidine,
MacMahon, O'Reagan, MacLysaght,
O'Kelleher, Boland, Cramer, Kearney,
O'Casey,
Power,
Twomey,
Eustace,
Ahearne,
MacGrath, Quick,
O'Meara, Scanlan, MacArthur,
Cosgrave,
O'Hogan, Lonergan and others. O'Noonan and Coombe are other notable
Uí Bloid descendants. Other families descended from the branch of Carthann (son of Caisin) include
Harley,
Flood, Torrens, Stoney,
Hickey,
O'Hay, Clancy, Neylon and
Flattery. Carthann had brothers named Eocha and Sineall from whom descend the
O'Grady,
Tubridy, Hartigan, Durkin, Killeen and
Hogg. In addition to this, there are the
Ui Fearmaic who claim to descend from Aengus Cinathrach, a brother of Caisin and Bloid. This kindred included the
O'Dea as leaders, as well as the
O'Quin,
O'Griffin / O'Griffey (chieftains of Cineal Cuallachta),
O'Heffernan,
Kielty and Perkin.
Titles and social roles Within the traditional
Gaelic culture of Ireland, society rested on the pillars of the tribal nobility, bardic poet historians and priests. Different families had different roles to play and in many cases, this was a hereditary role. However, the nature of this system, known as
tanistry was
aristocratic ("rule by the best") in the truest sense, in that if the tribe thought a younger male member of the family was more suitable to succeed to a role than an older sibling, then they could. The
Norman and wider European concept of strict
primogeniture was not completely adopted until after some of the families joined the peerage of Ireland. The most powerful Dalcassian family of the
hereditary Gaelic nobility were the O'Brien (Kings of Thomond), followed by MacNamara (Lords of Clann Cuilean), O'Kennedy (Kings of Ormond), MacMahon (Lords of
Corca Baiscinn), Even after the end of the Gaelic order, they continued to play a role, providing a
High Sheriff of Clare in the form of
Boetius Clancy. The
O'Hickey and
Neylon sept would serve as hereditary physicians to the Dalcassians of Thomond. After the Norman
Butler dynasty took Ormond, the Dalcassian sept of
O'Meara became their hereditary physicians, this line included
Barry Edward O'Meara, who was with Emperor
Napoleon I in exile at
St. Helena.
Chieftainship What became known as the Dál gCais stemmed from the Deisi Becc (Small Deisi) who controlled a narrow strip of land stretching from the Ballyhoura mountains to the Shannon and were divided into the Deisi Deiscirt (Southern Deisi, centred around Bruree) and Deisi Tuaiscirt (Northern Deisi, centred around Cahernarry) who shared a common ancestry. Their conquest of modern Clare probably occurred after the Battle of Carn Feradaig in 629AD where, under their king Díoma mac Rónáin, they defeated the King of Connacht
Guaire Aidne mac Colmáin who was invading Munster. After this, their Kings first appear in contemporary records. Andelait, son of Díoma is one of eight
Munster kings listed as guarantors of the
Cáin Adomnáin in 697. In 713 the Deisi Tuaiscirt killed the
King of Cashel Cormac mac Ailello in battle at Carn Feradaig after he had invaded their territories. In 744 the annals note: "
Destruction of Corco Mruad by the Déis" which indicates their power in Thomond was growing. In 765 the death of their king Torpaid is noted in the annals. From this point forward the annals are silent on the Deisi Tuaiscirt until 934. In 934 the annals report the death of Reabacán mac Mothla who is described as King of the Dál gCais (the earliest extant usage of this dynastic name) and Abbot of Tuaim Gréine and in the same year his son was killed by one of the sons of Lorcáin mac Lachtna (who is said to succeed Rebeacán as king), the annals report "
Duibhghiolla, son of Robacáin, Lord of Ua Corbmaic, was murdered by Congalach son of Lorcáin in treachery". This action must have paved the way for Lorcán and his sons to seize power. Lorcán was descended from the
Uí Toirdhealbhach instead of the
Uí Oengusso who had hitherto comprised the Deisi Tuaiscirt kings.
Cinnéidigh, another son of Lorcáin, who became king after his father, expanded the power of the Dál gCais greatly and was noted as
King of Thomond in the annals by his death. His son
Mathgamain built on his achievements, capturing
Cashel and becoming
King of Munster. The best-known member of this dynasty,
Brian Boru, took over after his brother Mathgamain's death, reclaimed the Munster kingship and eventually succeeded in establishing himself as
High King of Ireland before his famous death in the
Battle of Clontarf. The Dál gCais under Brian's descendants, the
Ua Briain would provide a further three
High Kings of Ireland and exercised supremacy in
Munster until
Tairrdelbach Ua Conchobair, taking advantage of war between brothers
Diarmait and former High-King
Muircheartach, invaded
Munster and split it in two in the Treaty of Glanmire (1118) granting
Thomond to the sons of
Diarmait Ua Briain and
Desmond to the leading sept of the dispossessed
Eoganacht, the
Mac Cárthaigh dynasty. After the death of
Domnall Mór Ua Briain, a claimant to the Kingship of Munster, they further retreated beyond the
Shannon into the area of modern
County Clare in the wake of the
Norman Invasion. In 1276
King Edward II granted all of
Thomond to
Thomas de Clare, taking advantage of the feuding between Clann Taidhg and Clann Briain (whom de Clare supported). The de Clares failed in conquering Thomond and were decisively defeated in the
Battle of Dysert O'Dea in 1318, thus the
Kingdom of Thomond remained outside of foreign control for a further 200 years. In 1543
Murchadh Carrach Ó Briain, agreed to
surrender his
Gaelic Royalty to
King Henry VIII and accepted the titles
Earl of Thomond and
Baron Inchiquin. At his death in 1551, the Earldom passed to his nephew
Donough by special remainder and the title
Baron Inchiquin passed to his male heirs through his son
Dermot. The Earldom went extinct at the death of
Henry O'Brien, 8th Earl of Thomond, the next heir would have been a descendant of
Daniel O'Brien, 3rd Viscount Clare who was
attainded in 1691, so the title became
forfeit. However,
Charles O'Brien, 6th Viscount Clare, a
Jacobite exile used the title Earl of Thomond, as did his son, who died childless in 1774. At the death of
James O'Brien, 3rd Marquess of Thomond, the title
Baron Inchiquin passed to a distant cousin and descendant of
Murrough,
Sir Lucius O'Brien, 5th Baronet and was passed down to his descendants. This early list of Dál gCais Kings is supplied in
An Leabhar Muimhneach.
Key: •
= King of Northern Deisi •
= King of Thomond •
= Baron Inchiquin •
= Viscount Clare •
= Earl of Thomond, Earl of Inchiquin •
= Marquess of Thomond A higher Kingship title which is mutually inclusive with a lower one within the dynasty are not given overlapping dates for the simplicity of the chart. {{tree chart|||||HEN||||||CHA||||||WIL||EDW||EDW=
Edward2nd Baronet of Leameneh1717-1765|WIL=
William3rd Earl of Inchiquin8th Baron of Inchiquin1692–1719|HEN=
Henry8th Earl of Thomond1691-1741|CHA= {{CSS image crop {{tree chart|||||||||||||CHA||WIL||JAM||LUC|LUC=
William4th Earl of Inchiquin9th Baron of Inchiquin1719–1777|JAM=
Jamesdied 1771|CHA={{CSS image crop {{tree chart|||||||||||||||||MUR||EDOM||EDW|EDW={{CSS image crop
Edward4th Baronet of Leameneh1795-1837|MUR={{CSS image crop {{tree chart|||||||||||||||||WIL||JAM||LUC|LUC=
Lucius5th Baronet of Leameneh1837-1855
13th Baron Inchiquin1855-1872|WIL={{CSS image crop ==Annalistic references==