  Ã ceallachÃ¡in, o'callaghan, or simply callaghan without the prefix, is an irish surname. often when irish immigrants migrated to the united states and passed through ellis island the "g" was removed from the spelling. ==origin and meaning== ===munster===  the surname means descendent of ceallachÃ¡n who was the eÃ³ganachta king of munster from ad 935 until 954. the personal name cellach means 'bright-headed'. the principal munster sept of the name callaghan were lords of cineÃ¡l aodha in south cork originally. this area is west of mallow along the blackwater river valley. the family were dispossessed of their ancestral home and  by the cromwellian plantation and settled in east clare. in 1994, don juan o'callaghan of tortosa was recognised by the genealogical office as the senior descendant in the male line of the last inaugurated o'callaghan. the callaghan land near mallow, forfeited by donough o'callaghan after the irish rebellion of 1641, came into the hands of a family called longfield or longueville, which built a 20-bedroom georgian mansion there. in a twist of history,  of the ancient callaghan land returned to callaghan hands in the twentieth century, when longueville house was bought by a descendant of donough o'callaghan.longueville house the ancestral estate of the callaghans, now a luxury hotel, is currently owned by william o'callaghan. ===oriel=== an entirely different sept, Ã ceileachÃ¡in in irish, is to be found in the counties armagh, louth, meath and monaghan. it has been anglicised as callaghan, kelaghan, keelaghan, kealahan and other variants. in county meath, where it is widespread but has been found mainly in the parishes of kells, trim and athboy, it is mainly anglicised as callahan, callaghan or o'callaghan (with local spelling variants). in county westmeath it is still found in the form kellaghan and kelleghan. in county monaghan it is often found as keelan.edward mclysaght: irish families, their names, arms and origins members of the Ã ceileachÃ¡in family were mentioned in the annals of the four masters as being lords of uÃ­ breasail, a district on the southern shore of lough neagh, and priors of armagh in the 11th century.annÃ¡la rioghachta Ãireann: annals of the kingdom of ireland http://defoxrecords.blogspot.co.uk/2013/07/to-what-end-nothing-left-to-burn-is-now.html#.uusm1bdfliu ==people== *barry o'callaghan, ceo and controlling shareholder o
Irish_families Surnames Surnames_of_Irish_origin