What is the history of the O'Leary surname?

Answer 1

O'Leary is a common Irish name, an anglicized version of the original spelling 'O Laoghaire' or 'O Laoire.' Early records of the name Lóegaire mac Néill are from Tara where High-King Laoghaire, a member of the Uí Néill clan, became the first Christian king of Ireland in 432 AD. The Uí Laoghaire clan, today associated with the Uibh Laoghaire parish in County Cork, is considered by scholars[1][2] to have originated on the south-west coast, in the area of Ros Ó gCairbre (Rosscarbery), of which the O'Leary were hereditary lords[3]. The Annals of Innisfallen (Dublin copy) records St. Fachtna's (Saint Fachanan) death in 600 A.D. as occurring in "O'Laeghaire of Ross i.e. Corca Laidhe-I-Laeghaire Ruis"[4]. The clan traces its lineage to High-King Lugaid mac Con who ruled in approximately 200 A.D. In the 12th century the O'Leary's were recognised hereditary wardens of St Fachtna's monastery and seat of higher learning, the School of Ross[5]. In more recent times(1300-), the clan, of the Corca Laidhe tribe, was pushed north and settled in an area south of Macroom around Inchigeelagh on the River Lee called Uibh Laoghaire (or Uibh Laoire in modern Irish - the 'gh' is silent in the old Irish).