MacMahon

MacMahon (Mac Mathghamhna MacMahon) is the surname of two unrelated families of medieval chieftains, the MacMahon vassals of the O'Brien princes of Thomond or north Munster, and the MacMahon kings of Oriel (Oirghialla), approximately Co. Monaghan. In the 12th century the Monaghan and Louth areas were ruled by the Ua Cerbaill (O'Carroll) family, whose power was extinguished by the Norman colonization of Louth. Then in the early 13th century the annals identify a new military power in the Monaghan area, as wielded by Niall MacMahon ‘with his bandits’. An early genealogy traces Niall to a collateral kinsman of the Ó Cerbaill kings, though the MacMahons were later to claim direct descent. Vassals of the Pipards and de Verdons in the 13th century, and of the earls of Ulster in the early 14th, the MacMahons won a brief independence before becoming subordinate allies of O'Neill from the late 14th to the 16th centuries.

Katharine Simms