Ímar Ua Donnubáin

Ímar Ua Donnubáin or Ivor O'Donovan, and possibly nicknamed Gilla Riabach, was a legendary and celebrated petty king, navigator, trader, and reputed necromancer of 13th century Ireland belonging to the O'Donovan family. He may or may not have been the second son of Cathal, son of Crom Ua Donnubáin, from whom the modern Clancahill dynasty descend. In any case Ivor is the ancestor of the historical O'Donovan sept known as the Sliocht Íomhair or "Seed of Ivor", who are generally considered to have been one of the four great septs of the family before being all but destroyed in the 1560s in a conflict with the Clancahill main line. Although mostly legendary, Ivor is possibly referred to in one or two near contemporary sources.

His name is the Gaelic for the Norse Ivar, and his associations are principally maritime. The O'Donovan family of the 10th, 11th, 12th, and early 13th centuries were associated with the world of the Norse-Gaels, although they lived in a region of Ireland distant from the great centres of that culture in the Irish Sea region. Ímar was a descendant and likely namesake of Ivar of Limerick and/or Ivar of Waterford through Cathal, son of Donnubán mac Cathail, who established friendly relations with the Norse of Limerick city and distant Waterford for himself and his descendants. Between the late 12th and early 13th centuries the majority of the family were forced to relocate to distant Carbery on the southern shores of Munster, and they early established themselves as absolute masters of the celebrated bay and harbour of Glandore, capturing it from the Normans. It is with this harbour and its environs that Ivor is exclusively associated.

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