[1] Recent DNA analysis confirms the history of the Three Collas in fourth-century Ireland, but questions their descent from Eochaid Doimlén and Cairbre Lifechair.
With an army drawn from Connacht, they fought seven battles in a week against the Ulaid at Achaidh Leithdeircc, killing Fergus Foga, king of Ulster, in the seventh.
They burned Emain Macha, the Ulster capital, after which it was abandoned, and seized substantial territories in mid-Ulster, thought to be the origin of the kingdom of Airgíalla.
The sixth century female saint, Derchairthinn, associated with Oughter Ard near Straffan, County Kildare,[citation needed] was said to be "of the race of Colla Uais, Monarch of Érinn".
O'Rahilly argues that the breaking of the power of the Ulaid, the destruction of Emain Macha and the establishment of the kingdoms of the Airgialla were actually accomplished by the three sons of Niall Noígiallach, Conall, Endae and Eógan, who established the kingdoms of Tir Eógan and Tir Conaill in north-western Ulster in the mid-5th century.
He believes the Three Collas are literary doublets of the three sons of Niall, their story a genealogical fiction intended to give the tributary kingdoms of the Airgialla a noble pedigree.
In regards to Colla, it may derive from the names Coill or Coel, both of which Geoffrey Keating mentioned in the area the Trinovantes lived, Camulodunum (modern-day Colchester).
The 232 testers are composed of 53 McDonald, 43 McMahon, 23 McKenna, 17 MacCan, 17 Duffy, 12 McGuire, 8 Hughes, 8 McQuillan, 8 Monaghan, 7 Boylan, 5 Hart, 5 Kelly, 4 Higgins, 4 McArdle, 4 MacDougall, 3 Carroll, 3 Cooley, 3 Larkin, 3 Neal, 2 Devine.