The Kennedy Clan of Ireland
Two Kennedy clans occupy the Emerald Isle: One is Irish and the other is Scots. Therefore, many confuse the two families and the lands they are from.
The majority of the Kennedys who settled in Northern Ireland are of Scottish origin from the territories of Galloway and Ayr just across the Irish Sea some 20 miles away. These Scottish Kennedys intermarried with local Irish and thus they are Scots-Irish in blood.
The other Kennedy family is located in southwest Ireland with its foundation in the bloodline of Cormac Cas, King of Thomond and Munster. Cormac Cas is the progenitor of the clan known as the Dal Cais or Dalcassians, translated to mean descendants of Cas. They were a minor clan of Ireland and ruled the northern section of Munster Province known as Thomond (all County Clare, southern Galway and northern Limerick, northwest Tipperary), while their cousins, the Eugenians (McCarthys and OSullivans) ruled the south of Munster known as Desmond. The kingship of Munster switched between these two clans every other generation.
Two great families came from the Dalcassian Clan: The OBriens and the OKennedys.
Cinneidigh (Kennedy), King of Thomond, died in 954 A.D. He was succeeded by his son, Brian. In time Brian rose in power and gained the kingship of Munster, obtained the allegiance of the other five provincial kings of Ireland, and eventually became High King of Ireland. Because he exacted tribute, his second name became Boru, meaning “tribute.” He is known as one of the greatest kings of Ireland, and in 1014 he defeated the Vikings at Dublin at the age of 88.
King Brian Boru decreed a law around 1000 that all families or clans should possess a surname and suggested that they should choose an illustrious ancestor after whom to name themselves. Due to his achievements, Brians family chose to call themselves OBrien, descendants of Brian.
One of his brothers was Donchuan (Duncan?), whose son was named after Donchuans father, Cinneidigh. It is this line from which the Irish OKennedys descend. They held the title of Lords of Ormond and were powerful until the 1500s. OKennedy/Kennedy is the 16th most popular name in Ireland, with the majority living in County Tipperary. Other strong areas are Clare and Dublin in the south and Antrim in the north (these being mostly Scots Kennedys).
Compiled by Garry Bryant.
Sources: Irish Families, Their Names, Arms, & Origins by Edward MacLysaght; Irish Pedigrees by John O'Hart; Great Families of Ireland, page 225; and If Youre a Wee Bit Irish by William Durning.