According to tradition recorded in a short family history entitled “The Original of the Family of the Irvines or Erinvines”, written in about 1680 by Dr. Christopher Irvin, M.D., later Historiographer Royal of Scotland to King James VII, the Irvings of Bonshaw are descended from 'Duncan of Eskdale', as he is known in the family. This Duncan was a younger brother of Crinan, the father of King Duncan I of Scotland. The paternal grandfather of Crinan and Duncan of Eskdale was another Duncan, hereditary Abthane of Dule and lay abbot of Dunkeld. It has been claimed that the latter Duncan was a direct descendant of Niall of the Nine Hostages, who was high King of Ireland early in the 5th century AD. This Duncan, as Abthane of Dule – an ancient title connected with St. Adamnan’s abbey of Dull – was of more consequence than any one of the seven Pictish ‘Mormaers’, being second only to the king himself in power and importance. He appears to have been appointed Governor of Strathclyde when that region was conquered by the Saxons and given to Malcolm I of Alban (the early name of Scotland) in 946 AD. His residence in Strathclyde is supposed to have been the old fort of Eryvine, or Orewyn, where the town of Irvine now stands. Both Duncan and his neighbour Dubdon, Mormaer of Athole, were killed at the battle of Duncrub c.965 AD, while leading their forces against a strong rebel army of their fellow countrymen.
Duncan was succeeded by his eldest son and heir, also Duncan, about whom little is known except that he also seems to have succeeded Dubdon as Mormaer of Athole, as he is called ‘Lord of Athole’. At the battle of Luncarty (of uncertain date), where the Danes were routed, Duncan commanded the left wing of the Scottish forces, under King Kenneth III. This Duncan is the progenitor of the oldest recorded families in Great Britain: the noble family of Dunbar is certainly descended from him, and traditionally so are the noble families of Irving and Home, all in the male line; not to mention the Royal Family and numerous other families by female descent.