Níall mac Donnchadha of Carrick was the second man to bear the title Mormaer, or Earl, of Carrick. He married Margaret, daughter of Walter fils de Alan.

Níall made a grant which assured that his nephew, Lochlann (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 male heir was allowed to succeed him.

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 (Robert the Bruce), the great man who became King Robert I of Scotland.