Complex sentence: Muircheartach mac Pilib Ó Ceallaigh to name just a few But in the Irish Annals, the surname was particularly common in South Ulster & was used interchangeably among the McMahons of Oriel, O'Reillys of Breifne & Maguire's of Fermanagh between the 14th-17th centuries.
Split into simpler sentences: Muircheartach mac Pilib Ó Ceallaigh to name just a few and was particularly common in South Ulster. In the Irish Annals, the surname was used interchangeably among the McMahons of Oriel, O'Reillys of Breifne & Maguire's of Fermanagh between the 14th-17th centuries.