ABSTRACT
The Mac Mahon (Mac Mathgamna) family were Gaelic lords of Airgialla (Oriel), approximating to what is now County. Monaghan, during the late medieval period, on the marchlands of Gaelic Ulster and the northern Pale. They are first mentioned in the annals in 1181, and were related to the previous Ua Cerbaill ruling dynasty of Airgialla who surrendered the lordship to the Mac Mahons in the late twelfth century. The Mac Mahons were a border people, who came alternately under pressure from Ua Néill, lord of Tír nEógain, and the Anglo-Irish of Louth. Throughout the entire medieval period the Mac Mahon lordship was also a relatively poor region. There were no important religious houses or Mac Mahon castles, although during the fifteenth century the Mac Mahon lords did become noted patrons of bardic poets.
