Dál gCais
The Dalcassians · the share or portion of Cas, a people reckoned from an ancestor named Cas
Dál gCais, in English The Dalcassians, said dawl GASH. A ruling kindred.
The people who came from nowhere in the tenth century, took Munster off the Eóganachta, and produced the one high king everybody can name.
The name
the share or portion of Cas, a people reckoned from an ancestor named Cas
Where
East Clare at the start, then north Munster either side of the lower Shannon.
In today's counties: Clare (An Clár), Limerick (Luimneach), Tipperary (Tiobraid Árann).
When it mattered
The tenth and eleventh centuries, from Mathgamain and Brian Bóruma onward.
In the ninth century the Dál gCais were a small people in east Clare, under the name Déis Tuaiscirt, the northern Déise. That word déis again: clients, vassals, nobody's first guess for a royal line.
The Viking wars changed who mattered. Fighting along the Shannon suited a people who lived on it, and within two generations the Dál gCais had taken the kingship of Munster from the Eóganachta. Mathgamain took Cashel; his brother Brian Bóruma took everything else, and by 1002 was being called king of Ireland.
Brian was killed at Clontarf in 1014, on the day his army won. His descendants took the surname Ó Briain, and Thomond stayed theirs for five hundred years, which is longer than most dynasties in Europe managed.
Where the usual story goes wrong
The grand Dál gCais pedigree, tracing them back alongside the Eóganachta as equals since antiquity, was written up after they were already in power. It is a claim made by winners, not a record.
What is left of the name
Thomond, the kingdom they built, still names a rugby ground, a bridge and a park in Limerick.
Names out of it
Families on this site that belong to The Dalcassians. A surname is not a pedigree, and plenty of people carry these names for reasons that have nothing to do with the old kingdom.
- O’Brien (Ó Briain)
- MacNamara (Mac Conmara)
- Kennedy (Ó Cinnéide)
- Hogan (Ó hÓgáin)
- Hickey (Ó hÍcí)
- Ahern (Ó hEachthigheirn)
Next to it
- Tuadhmhumhain (Thomond)
- Na hEóganachta (The Eóganachta)
- Na Déise (The Déise)