Mac Riabhaigh (MacGrievy, McGrievy, MacGreevy, McGreevy, Magreevy, Magreavy) which see; the name of a family who was anciently chiefs of Moylurg, in Co. Roscommon [Sloinnte Gaedheal is Gall].
Mac Diarmada (MacDermott, McDermott; MacDermot, McDermot; MacDermod, McDermond; McDermottroe; Dermody etc).
Descendant of Maolruanaidh' (follower of Ruanaidh; the name (1) of a Fermanagh family ... (2) of a Galway family... (3) of a Dalcassian family ... Clare, Limerick and Tipperary ... corrupted to Moroney, and (4) of a Roscommon family who afterwards adopted the surname of Mac Diarmada, or MacDermott, [Sloinnte Gaedheal is Gall].
- Son of Diarmaid' the most important family of this name are the MacDermotts of Moylurg. they were a branch of the Sil-Murray, long the ruling race in Connacht, of which, next to the O'Connors, they were the most powerful family. Their clan-name was Clann Mhaoilruanaidh, so called from Maolruanaidh, who was son of tadhg O'Connor, king of Connacht, in the 11th century. they are, therefore, of the same stock as the O'Connors.
- From Diarmaid, who was the grandson of Maolruanaidh and died in 1159, they took the surname of Mac Diarmada, anglicised MacDermott.
- About the middle of the 14th century, they divided into three distinct septs, each with a chief of its own, namely:
- MacDermott of Moylurg, who was overlord of all the MacDermotts, and had his fortress at the Rock of Lough Key, near Boyle;
- MacDermottroe, or the red MacDermott, who was chief of Tir-Thuthail, comprising the parish of Kilronan, and had his residence at Alderford; and
- MacDermottt Gall (or gallda), the English or Anglicised macdermott, who was chief of Artagh, comprising the parish of Tibohine.
- The two baronies of Boyle and Frenchpark now represent the patrimony of the MacDermotts. The McDermotts played a conspicuous part in the history of Connacht. They retained their rank as Lords of Moylurg down to the end of the 16th century; and as successors to the O'Garas continued to hold considerable property at Coolavin, in co. Sligo, down to recent times; and the MacDermott is still known as the Prince of Coolavin. [Sloinnte Gaedheal is Gall]