LIMERICK (county of), ANCIENT THOMOND in the province of MUNSTER, bounded on the north by the estuary of the river Shannon and the county of Tipperary; on the east by the county of Tipperary; on the south by county Cork, and on the west by county Kerry. Of the tribes mentioned by Ptolemy, the Coriondi appear to have inhabited this portion of Ireland; and although from a very early period it was included in the native kingdom or principality of Thomond, it is said to have had at one time a separate political existence, under the name of Aine-Cliach, or Eoganach-Aine-Cliach, and to have been divided into five cantreds, governed by subordinate chieftains. That of Carrigoginniol belonged to the O'Kiarwicks, and afterwards to the O'Briens, whence the name of Pubblebrien was given to the barony; Uaithney, now the barony of Owneybeg, belonged to the O'Ryans; Cairbre Aobhdha, or Kenry, to the O'Donovans. For purposes of civil jurisdiction it is divided into the baronies of Clanwilliam, Lower Connello, Upper Connello, Coonagh, Coshma, Costlea, Kenry, Owneybeg, Pubblebrien, and Small County; Lower Connello is subdivided into the barony of Lower Connello East, and the division of Shanid; and Upper Connnello, into that of Upper Connello East, and the division of Glenquin; these arrangements have been found necessary from the great extent of the baronies, which comprised fully one-half of the county; the new divisions were named after the castles whose ruins are conspicuous near their respective centres.

On the south-east, the plain country is bounded by the Galtee mountains, rising precipitously to a great elevation, forming the boundary of county Limerick, and stretching thence far into the county of Tipperary. The Galtee Mountains or Na Gaibhlte in Irish are a mountain range in Munster, located in Ireland's Golden Vale across parts of counties Limerick, Tipperary and Cork. The Galtees are Ireland's highest inland mountain range, taking the form of a high ridge which rises up almost sheer from the surrounding plain. The Galtees were formed during the Caledonian Foldings, which caused the underlying Silurian rocks to fold into great ridges. On the north-east the barony of Owneybeg embraces the skirts of the Slieve Phelim mountains, which forms an extensive group penetrating the interior of Tipperary. At the turn of the last century Dineen and Dinneen were the two preferred spellings of the name, both of which were centered in Co. Cork. Earlier in the census of 1659, Dinane was a principal name of county Cork".

Clanwilliam - named for the Clanwilliam Burkes. The O'Cuircs (O'Quirkes) were noted here in the 11th and 12th centuries as kings of Muscraige Cuirc, sometimes called O'Quirkes Country. The O'Heffernans are cited here after being displaced by the Ryans from Owney and Owneybeg baronies. Also see County Tipperary. The Ó Conaings (O'Gunning), a sept of the Uí Bloid, were noted with territory near Castlegunning (Castleconnell) prior to being dispossessed by the MacWilliam Burkes in the 13th century.

Owneybeg - Uaithney was the name of the Eoghanacht cantred here, controlled by the O'Maoilriain (O'Mulryan or O'Ryan) who were cited as chiefs of 'Owney Mulryan' which included both Owneybeg, and Owney in Co. Tipperary. Mac Eochaid (MacKeogh) were cited as chief of Uaithni Tire, or Owney, which also included the barony of Owney and Arra in Co. Tipperary. O'Dinan (Dinnahane) is cited as chiefs of Uaithne here, as hereditary chiefs of the Eoghanacht Uaithne Agamar. Ó Cathaláin (O'Culhane) is cited as a chief of Owney Beg before being dispossessed by the O'Mulryans in the late 12th/early 3th centuries.

O'Duinechair and O'Dinan, chiefs of Éoganacht Uaithne Ageamar [Owney Agamar]. This territory comprised part of the counties of Tipperary and Limerick, now the baronies of Owney and Owneybeg. The sept of O'Cahalane or Culhane (Ua Cathalain) was noted as Lords of Owneybeg, a portion of the territory belonging to Clann Uathnia. Clann Uathnia was comprised of two parts; Uaithni Thíre (parts of the barony of Owney and Arra in County Tipperary) and Uaithni Cliach (approximately the barony of Owneybeg in County Limerick). In the Annals there is a mention of Cuilen Ua Cathalain, Lord of Uaithne Cliach, who died in 1107. Prior to the anglo-norman invasion, the territory in the barony of Owney and Arra was known as Eoghanacht Aradh or Aradh Cliach, where the O'Cuillens (O'Cullens) were noted as chiefs. The Uí Bhrian, a Dalcassian sept, were lords of Owney & Arra, the territory they acquired from the O'Donegans about 1300.

Owney and Arra - O'Cuillen (O'Cullen or Collins) were cited as chief of Eoghanacht Aradh. Mac Eochaid (MacKeogh) were cited as chief of Uaithni Tire, or Owney, which also included the barony of Owneybeg in Co. Limerick. The O'Maoilriain (O'Mulryan or O'Ryan) were cited as chiefs of 'Owney Mulryan' which included both Owney and Owneybeg. Another sept here included Mac Uí Bhrian (Mac I Brien), lords of Owney and Arra, their territory anciently referred to as Aradh Cliach and acquired from the O'Donegans around 1300. O'hIfearnain (O'Heffernan) is cited as chief of Uaithne Cliach here prior to the Ryans. The 'Book of Rights' cites the "four tribes of Owney" as O'Heffernan, MacKeogh, O Loingsigh (Lynch) and O'Calahan.