Mac Raghnaill some are of Irish origin, others of Scottish origin, some are of English origin, and some may be of Norwegian and or Danish origin. Mac Raghnaill Mac Raghnaill is masculine surname in the Irish language. The name translates into English as "son of "Raghnall"". The surname originated as a patronym, however it no longer refers to the actual name of the bearer's father. The name "Raghnall" is a Gaelic derivative of the Old Norse personal name "Røgnvaldr" / "Rǫgnvaldr" / "Rögnvaldr". Variant forms of the surname include Mac Rághnaill and Mac Raonaill. These three surnames can be Anglicised variously as:
Eolais mac Biobhsach manuscripts going back almost two hundred years. O'Donovan claimed the family name ( "descendent of Eolais") is still found anglicised as "Olus" or "Olis". two instances of the surname corrupted as "Oelase" and "Olase", are found in the Irish Fiants for Leinster. The surname must be very rare. Eolais mac Biobhsach Eolais "mac Biobhsach" (alias " "knowledge", anglicized "Wallis", "Olis" or "Olus" ) was a chieftain of 10th century Gaelic Ireland. He is noted as the first "full chieftain of Conmaicne Réin". His descendants, "the Muintir Eolais", expanded into the territory of present day south county Leitrim, and parts of