This site is devoted to revealing the history of Clan Mac Mahon of Oriel, so that all those who are descended from this lineage may know the true nature of their legacy. This includes the following surnames: McMahon, Mac Mahon, Mahon, Mathews, McArdle, McPhillips and others. Counties Monaghan, Armagh, Fermanagh, Louth and Derry, Ireland and Beyond ....