Ireland: Leaders

Historical Gaelic Regional Rulers 


The Ulaid ruled as over-kings of the ancient cóiced (portion, fifth) of Ulster up till about 450 AD. Ptolemy‘s map of Ireland (compiled about 150 AD from many earlier sources) shows the Ulaid as the Voluntii and adjacent Darini. In their prime they seem to have been direct rulers of what are now County Monaghan, County Armagh, County Down, County Antrim and much of County Louth. The centre of the province was held by the Airgíalla, who were vassals of the Ulaid, and later the Uí Néill. Ptolemy’s map lists two tribes further west, the Vennikinii in County Donegal and the Erpitianni along lower and upper Lough Erne; both were probably subject to Ulaid rule.

The ancient Ulaid capital of Emain Macha was attacked and destroyed c.325 AD by the three Collas from Connacht. From that point onwards the Ulaid were slowly reduced to being mere chieftains of their homelands east of the upper and lower River Bann, which was Ulaid proper. Yet as late as 1080, king of Ulaid Aed Meranach Ua hEochada attempted to revive the fifth complete with Ulaid over-kingship.

After the C5th western Ulster was dominated by the kings of Ailech of the Northern Uí Néill, the Cenél nEógain and Cenél Conaill. Following the fall of Ulaid (eastern Ulster) in the early C13th, the Gaelic kings of Ulster came exclusively from the Cenél nEógain, the kings of Tír Eógain (Tyrone). These were the O’Neill dynasty and the MacLochlainns, the latter surrendering their claim to the title in the mid-C13th.

The Uí Néill /O’Neill dynasty dominated most of medieval Ulster from their base in Tír Eóghain (“Eoghan’s Country”, most of which is now in County Tyrone).

The Earldom of Ulster passed into the hands of the Norman de Burgo clan, who ruled Connacht, but collapsed in 1333 when it was superseded by the Clandeboye O’Neills.

The first O’Neill king of Ulster was proclaimed in 1364.

Ulster’s second most powerful clan was the Ó Domhnaill / O’Donnell dynasty who ruled over Tír Chonaill (“Conal’sCountry”, now County Donegal) from the early C13th until the beginning of the C17th.


The Cuige Chonnacht came into being in the early medieval era, and was named after the Connachta, a group of dynasties who claimed descent from the three eldest sons of Eochaid Mugmedon: Brion, Ailill and Fiachrae. They took their collective name from their alleged descent from Conn Cétchathach. Their younger brother, Niall Noigiallach was ancestor to the Uí Néill.

The  kingdom held the primacy of Ireland’s five Cuigí under its C12th ruler Ruaidrí Ua Conchobair / Rory O’Connor, who was acknowledged Ard Rí / High King. After the Normans invasion, he had little option but to submit to King Henry II, retaining the title  king of Connacht under the Treaty of Windsor 1175.

The remnant of the O’Conor family maintained the title of king of Connacht during the Middle Ages with kings inaugurated officially up until the late C17th. The ruling O’Conor Don family have survived until the present day


The Eóganachta / Eoghanachta (“Eugenians“)  were a dynasty centred around Cashel which dominated southern Ireland from the C6/7th to the C10th and subsequently held the kingdom of Desmond, and its offshoot Carbery, until the late C16th. By tradition the dynasty was founded in the late C5th by Conall Corc  but named after his ancestor Éogan, the firstborn son of the semi-mythological C3rd king Ailill Aulom.  Read more here.

Nearly all Kings of Cashel from the C5th to the C10th came from the three “inner” princely houses of Eóganacht Chaisil (MacCarthy, O’Sullivan, O’Callaghan, MacAuliffe, MacGillycuddy) , Eóganacht Áine  (O’Kirby, O’Kirwick/Kerwick) and Eóganacht Glendamnach (O’Keeffe).

Some were strong, others were renowned bishops and scholars, and others were weak. The importance of the Cashel kingship was primarily ceremonial, and rulers were with the occasional exception not militarily aggressive, although they continually strove for political dominance as far as they could with the province’s wealth. The most famous Eoganacht king was probably the legendary fighter and scholar Cormac mac Cuilennáin (d. 908).

Strong petty kingdoms regarded as subject would receive large payments called rath in return for their acknowledgement of the political supremacy of Cashel, and they would sometimes give hostages as well. The most powerful petty kingdoms exchanged hostages with the king of Cashel, and though subject in some sense (by agreement), they were legally free and capable of terminating the contract.



Following a period of  civil wars, the prehistoric kingdom of Laigin was re-founded c. 175/185 AD by the legendary Cathair Mor.

In the C5th, after Magnus Maximus left Britain with his legions, leaving a power vacuum, colonists from Laigin settled in North Wales, specifically in Anglesey, Carnarvonshire and Denbighshire. The Llyn Peninsula is generally believed to derive its name from Laigin (although some contrarians contend that “Leinster” means “Land of the men of the Llyn Peninsula”).

Laigin split into two in the early C8th; a northern dynasty was founded by the Uí Dúnlainge chieftain Murchad mac Brain, (d. 727), while a southern dynasty was established by the Uí Cheinnselaig / Hy Kinsella chieftain, Áed mac Colggen (d. 738). Amazingly, these two dynasties co-existed more or less peacefullyfor some 300 years, regularly alternating on the throne .

When the last northern chieftain, Murchad Mac Dunlainge, died in 1042, the kingship of Leinster reverted to the Uí Cheinnselaig sept, which came to be known as the MacMurrough Kavanagh dynasty.

Mide ( Meath)

According to tradition, the kingdom of Mide was created around the first century AD by Tuathal Teachtmhar. Its early kings may have been of the Uí Enechglaiss clan. Ptolemy’s C2nd AD map of Ireland labels the region as “Domnainn” with a capital at Rheba; this is thought to refer to the Fir Domnann, a branch of the Fir Bolg that included the Uí Enechglaiss (along with the Uí Failge and Uí Bairrche).

At the beginning of the C6th the Uí Enechglaiss were driven away over the Wicklow Mountains to an area near Arklow, where their ruling dynasty later took the surname O’Feary.  They were forced out of Mide by the Uí Néill / O’Neill clan, a sept of which, the Clann Cholmáin, took their place and ruled as kings of Tara and later titular Ard Rí / High Kings of Ireland for several hundred years.

Known by the medieval era as the Ua Mael Sechlainn /  O’Melaghlin dynasty, they were forced west after the late C12th Norman invasion and collapse of the kingdom.

Norse Rulers


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