Facts and Events
Níall of Carrick (also Neil) was the second man to bear the title Mormaer, or Earl, of Carrick. He was successor of mormaer Donnchadh of Carrick. He may have been Donnchadh's son, or else as suggested by one recent genealogical theory, his grandson. It has been argued that Niall's father was Nichol (Cailean or Colin), son of mormaer Donnchadh by the daughter of Niall Ruadh, briefly king of Tir Eoghain.
Níall made a grant which assured that his nephew, Lachlan and successors would have all the powers in respect to the ceann ceneóil (head of kin). This grant was confirmed by King Alexander III. It ensured that the structure of Carrick's Gaelic society would remain pretty undisturbed in the event that no direct male heir was available to succeed him as earl.
As things transpired, this is indeed what happened. Níall left no sons, and was succeeded by his daughter Marjory. The latter passed the mormaerdom on to her son Roibert a Briuis, who became King Robert I of Scotland.