The Kings of Magh Luirg or Moylurg were a branch of the Síol Muireadaigh, and a kindred family to the Ua Conchobair Kings of Connacht.
Their ancestor, Maelruanaidh Mor mac Tadg, was a brother to Conchobar mac Tadg, King of Connacht 967–973, ancestor of the O Connor family of Connacht.
Maelruanaidh Mor mac Tadg is said to have made a deal of some nature where, in return for abandoning any claim to the provincial kingship, he would be given Moylurg.
The following is a list of their Kings, followed by the respective heads of the family up to the early modern period.
The Kings of Moylurg The MacDermot of the Carrick The Chief of the Name