This is an anglicization of the Gaelic name 'O Laoghaire' which translates as 'grandson or male descendant of Laoghaire' - a popular personal name in ancient Ireland meaning 'calf herd'. O'Leary is the more usual anglicization of the name. The sept belonged to Co. Cork where they ruled as chiefs under the MacCarthys. Two place names Ballyleary (in Co. Cork) locate them. The O'Learys took a prominent part against English invaders in Munster and distinguished themselves in military service abroad. The name is found in the 18th century French regiments. The Learies were important in the literary field. Peadar O Laoghaire (1839-1919) was called 'the greatest living master of Gaelic prose'. The first recorded spelling of the family name is shown to be that of O' Laoghaire which was dated 1654 Civil Survey of the barony of Muskerry (North West and Central Cork during the reign of Commonwealth in England 1649-1659. Surnames became necessary when governments introduced personal taxation. In England this was known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.