The "three lions rampant" in the arms of the O’Beolain earls of Ross are unique in Scotland, and in Ireland occur only in the arms of families with ecclesiastical affiliations with the Connacht area (witness the arms of the O’Scanlans, O’Horans, O’Garas and O’Kearneys). Even the "three lions passant" of the Dalcassian O’Briens may reflect a Connacht connection. Considered the short genealogy of the Uí Toirdealbhaigh, their late acquisition of Dalcassian leadership (which was based on the success of the Uí Toirdealbhaigh against the Vikings), and also the fact that a number of Connacht families spread south as either ecclesiastical (O’Scanlan) or temporal (O’Heyne and O’Cahill) families. A number of medieval families considered "Dalcassian" are known to have origins in Connacht, including the O’Heaneys, O’Hehirs, O’Markahans and O’Kearneys. Though their primary identification was with Cashel in Munster, the O’Kearneys also had connections with the Columban foundations at Derry and Drumcliffe.
The Roses (Rois, Ros) take their name from the district of Ross in northern Scotland, and are connected with the O’Cahans by the Clan Donald seanachies (historians). Hugh Rose of Geddes witnessed the foundation charter of Beauly Priory by the Bissets (Antrim). They acquired their principal holdings, the Barony of Kilvarnock in Nairnshire, by marriage with an heiress. They may have acquired their O’Cahan connection win the same way, by marriage, and may originally have been of Norman origin.
The O’Cahans or O Cathain were a great family in County Derry, sub-kings of the Cenél Eoghain, whose heads were privileged to be one of the hereditary inaugurators of the Ó Neill. They and Clan Cian rose to great power during the twelfth century, and were lords of Keenaght, (Clan Conchobair) being possessed of the greater part of what is now County Derry until their lands were confiscated by the English in the Ulster Plantation of the sixteenth century. A branch (O' Dea) settled in Thomond -Innis Diamain (northeast Munster) and Tipperary (Owneybeg). There is a sixteenth-century O’Cahan knight’s effigy at Dungiven in County Derry. The Monros (Mac an Rothaich), derive their name from a place at the foot of the River Roe in Derry, and according to the Clan Donald tradition, they came into Scotland in the train of a daughter of the O’Cahan that became a MacDonald princess. They possessed the vast district of Foulis on the Cromarty Firth in Ross, and also lands in Strathoykell. The first known Munroe of the race is said to have been a certain Donald O’Ceann, of the time of Macbeth.
The O’Hagans (O hAgain) of the Cenél Eoghain descend from Tighearnach, who was a son of Muireadhach mac Eoghain, and thus a grandson of Eoghain, the eponymous ancestor of the clan. They were divided into two groups: The main being chiefs of Cineal Fearghusa, a territory around Tullaghoge or Tullahogue in County Tyrone (Tir Eoghain), and the other being chiefs of Cenél Tighearnaigh in County Derry, where their presence is recalled by the place called Ballyagan (there is another Ballyhagan in Antrim). It was the hereditary privilege of the O’Hagans to inaugurate The Ó Neill at their seate of Tullahogue (along with the O’Cahans). O'Hegarty sept of the Cenél Eoghan
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