Ancient territories of Ireland

The following ancient territories in existence from earliest times are mentioned frequently in the consideration of particular surnames. The Danes arrived between the ninth and twelfth centuries. They founded Dublin in 852, and their chief towns were Dublin, Wexford, Waterford, Cork and Limerick.

Anaghaile (Annaly) This comprised Longford. This was the territory of ó Fearghail, ó Cuinn.

Breifne (Breffny) This comprised Cavan and western Leitrim. This was the territory of ó Raghallaigh.

Corcu Lóighdhe This comprised south west Cork. This was the territory of ó Ceallaigh, ó Ceallacháin.

Dál Riada This comprised north Antrim. The ó Loingsigh were driven from here after the Cambro Norman invasion.

Déise (Decies) This comprised west Waterford.

Deas Mhumhan (Desmond) This comprised part of Cork and Kerry. The ó Súilleabháin established themselves in the west of Desmond. The Mac Carthaigh were Kings of Desmond.

Iar Connacht This comprised mainly Connemara.

Muscraidhe (Muskerry) This comprised central and north west Cork.

Orghialla (Oriel) This comprised Armagh, Monaghan and parts of south Down, Louth and Fermanagh.

Ur Mhumhan (Ormond) This comprised part of Kilkenny and north Tipperary. The ó Cinnéide became Lords of Ormond after being driven out of Clare.

Tir Chonaill This comprised west Donegal. This was the territory of ó Domhnaill, ó Baoighill, ó Gallchobhair. As the Mac Lochlainn declined in power the ó Dochartaigh a leading sept of the Cineál Chonaill became rulers of Inishowen.

Tir Eoghain This comprised Tyrone and the barony of Loughshinlon in Derry. This was the territory of the ó Néill. The original territory was Inis Eoghain the chief sept of which was the Mac Lochlainn.

Thuas Mhumhan (Thomand) This comprised Clare and Limerick. This was the territory of the Dál gCais septs such as ó Briain,

Uí Mhaine This comprised parts of Galway, Mayo and Roscommon. This had been the territory ó Muireadhaigh.


Barony A territorial division imposed on Ireland by the Normans, sometimes co-extensive with, or composed of a number of the ancient Gaelic Tuath. There are 273 baronies and from the sixteenth century they were used as an administrative unit.

Brian Bóirmhe High-king of Ireland lived from 926 to 1014, reigned from 1002 until his death at the Battle of Clontarf. He was chief of the Dál gCais of Thuas Mhumhan (Thomond).

Cambro-Normans Those Normans who having settled in Wales accepted the invitation of Diarmuid MacMurchadha to come to Ireland. In course of time it was stated that their descendants became more Irish than the Irish themselves (Hiberniores Hibernicis ipsis).

Clann A large tribal unit in Gaelic society which bore the name of a common ancestor. The septs later emerged out of the clanns.

County Ireland began to be shired by the English government from the thirteenth century, and the process ended with Wicklow in 1606. These became the principal administrative units of local government.

Diocese These are administrative divisions of the Church, presided over by a Bishop. Many of these boundaries date from the twelfth century, and reflect secular boundaries of that time.

Elizabeth I Queen of England from 1558, lived from 1533 to 1603. Known to the Irish as “Bloody Bess”.

Erenagh (aircinnech) The head of a church or abbey, who was a lay lord and whose family held such office for generations.

Galloglass Mercenary soldiers usually from Scotland.

Niall Naoi-Ghiallach Historical high king of Tara who may have died around 454. It was said that he held hostages from each of the five provinces, as well as from the Scots, the Saxons, the Britons, and the Franks. His descendants known as the Uí Néill were most powerful for 600 years, they divided into a northern and southern branch. Normans William Duke of Normandy invaded England in 1066, with the defeat of King Harold, William became King.

Pale, The The area around Dublin under control of the English government. It varied in extent through time.

Parish An area over which a local church exercised jurisdiction. Churches may have been administered by particular families. There are 2,445 civil parishes in total.

Plantation Beginning in the sixteenth century parts of Ireland were settled with English and later Scots settlers.

Sept The extended family unit in Gaelic society which adopted and bore a hereditary surname based upon the personal name of a common ancestor, and who occupied the same territory.

Strongbow Richard fitz Gilbert de Clare, lord of Strigoil and earl of Pembroke, landed in Ireland in 1170 at the invitation of Diarmuid MacMurchadha. He later established himself in Leinster.

Townland The smallest administrative division which relate to ancient Gaelic divisions. There are approximately 62,000 townlands.