An Introduction

Irish hereditary surnames date back to the 11th century and are among the oldest in the world. They developed spontaneously, as the population increased but there seems to be no grounds for accepting the suggestion that the system was introduced by Brian Boru, who died in 1014.

Initially surnames were formed by placing ‘Mac’ in front of the father’s name or ‘O’ before that of a grandfather or earlier ancestor. Names with the prefixes ‘Mac’ and ‘O’ were found in records which pre-date the tenth century but these did not last. In general, Mac is associated with the northern half of the country and the O with the southern portion.

Later, other surnames were adopted incorporating the Irish words giolla and maol, both meaning ‘servant’ or ‘follower’ and often used in conjunction with the name of a saint. Thus we have Mac Giolla Mhartáin which translates as Gilmartin or Martin. Likewise, Mac Giolla Mhuire (son of the servant of Mary) translates as Gilmore.

Similarly, many surnames are derived from the occupation of the father or grandfather. Mac an Bhaird (son of the bard) translates as Ward, while the earliest form of O’Riordan, Ó Rioghbhardáin indicates the surnames owes it origins to the position of ‘royal bard’.

Less frequently surnames indicate characteristics of an ancestor. The name MacDowell owes its origin to the phrase ‘black stranger’. Some surnames have their roots in nicknames. Names such as McAvaddy and Madden have their roots in the word madra, the Irish for dog.

Other surnames owe their existence to epithets indicating some personal characteristic added to the Christian or surname which eventually replaced the original name. Some surnames without the prefix ‘Mac’ and ‘O’ evolved in this way, with bán (white) becoming Bane and ruadh (red) becoming Roe.
Most of the surnames in Ireland today are of Irish origin, even in Ulster but the proportion there is smaller. Many of the surnames found there were introduced during the Plantation of Ulster in the 17th century. However the relationship between the peoples of Ireland and Scotland is more complex than that.

The Gaelic speakers of the highlands of Scotland were descendants of settlers from Ireland. The name Scotland is derived from the word Scotus the Latin for Irishman. In Ireland surnames with ‘O’ outnumber those with the prefix ‘Mac’. The latter prefix is not necessarily a sign of Scottish origin, nor is there any reason to suggest that ‘Mac’ is indicative of Scottish origin and ‘Mc’ a sign that the name belongs to Ireland. ‘Mc’ is simply an abbreviation of ‘Mac’.

During the era of suppression of Catholic Ireland which began in the early 1600s the use of prefixes ‘O’ and ‘Mc’ or ‘Mac’ was widely dropped and only revived with the re-emergence of national consciousness in the late 19th century. In 1866 only 4% of the (O) Sullivan family were using the prefix O, by 1890 it had increased to 13% and by 1944 reached 60%. Another example is that of the (O)Connells, where use of the prefix increased from 9% to 33% between 1866 and 1890.

Interestingly, many surnames of the ‘O’ variety have never revived the prefix, including the most numerous Irish surname of all, Murphy. Others to fall into this category include Connolly, Donnelly, Doyle, Foley, Hogan, Kennedy, Nolan, Quinn and Sheridan. Among the O’Brien’s and O’Neill’s the prefix was widely retained, while the equally important O’Kelly family generally discarded the prefix.

The prefix ‘Mac’ has proved more resistant to change, partly because of its existence among Scottish surname in Ulster, but also because deletion of the prefix greatly alters the appearance of the name. There is little discernible difference between Brien and O’Brien, but the opposite is true of McGrath and Grath. However where ‘Mac’ has been dropped there has been little effort to revive it. Names such as Clancy, Egan and Keogh originally had the prefix ‘Mac’.

In some cases the resumption of prefixes led to the adoption of the wrong prefix, with the substitution of O for Mac being more common.

The introduction of the English language had a distorting effect on many Irish names as many of those preparing legal documents had no knowledge of the Irish language. Most of the MacGowan’s (Mac an Ghabhann = son of the smith) of County Cavan became Smith by translation. A native inferiority complex also had a distorting impact on Irish surnames.

Mistranslation had a devastating impact on some Irish surnames. Mac Giolla Eoin (son of the servant of John) became Monday instead of McAloon because of the supposed similarity between the latter part of the name and luan the Irish word for Monday. In some cases the name McEneaney has become Bird due to the mistaken notion that the former is derived from the Irish word éan which means bird.

Some surnames came about through abbreviation. MacLysaght or Lysaght was originally translated from the Irish Mac Giolla Iasachta as Macgillysaghta. Others came about through a crude process combining abbreviation with distortion as in Muckle, which is short for Mucklebreed, which itself is derived from Mac Giolla Bhríde (son of the servant of St. Brigid).

Many distortions, abbreviations and mistranslations of Irish names took place when people were part of the mass migration to the United States of America in the late 19th century. Many emigrants were illiterate and immigration officials often mistranscribed them. Farrelly became Farley and Connolly became Conley in some cases. McEneaney, McAneaney, McAneny, McEnaney are all variant spellings of the same surname

The process of absorption has seen some rare names being replaced better known ones with a similar sound. For example, Sullahan became Sullivan, Griffey became Griffin, Collen became Cullen and MacEnchroe became Crowe.

Apart from native Irish surnames there are many of Norman origin which are now regarded as Irish, including such names as Burke, Cusack, Dillon, Nagle, Power, Roche and Taaffe. Costello was the first Norman name to become completely gaelicised and adopted the Mac prefix. Most Norman surnames retain the prefix de in their Irish form, e.g. de Búrca (Burke), de Róiste (Roche), de Paor (Power).

Sometimes the use of de can be misleading. A branch of the Devlin family changed their name to D’Evelyn for the sake of appearances. Similarly there are instances where Mullins was changed to de Moleyns.

Some surnames of Norman origin begin with Fitz, derived from the French fils meaning son. The best known of these is Fitzgerald, which translates as Mac Gearailt in Irish. Fitzpatrick (Mac Giolla Phádraig in Irish) is an exception as it of Irish origin.

Harold and Trant are examples of the few pre-Norman Norse names found in Ireland. Names such as Lefroy, Lefanu, Trench, Guerin and Saurin were part of the Huguenot influx in the 17th century. Ruttle and Switzer are examples of Palatine names found in Co. Limerick.

Last but by no means least are the surnames of English origin. Some are in evidence since the Middle Ages but most arrived relatively recently. The Bagenals and the Edgeworths are among the Elizabethans settlers in the 16th century. The Plantation of Ulster in the early 1600s and the Cromwellian settlement in the middle of the same century saw the widespread introduction of English and Scottish names.

The Cromwellian settlement saw immigration to most parts of the country and in succeeding generations many of those settlers intermarried with the native population. Names include Woodcock and Upton.

In the last two hundred years commercial activity has led to the introduction of a small number of additional English surnames. Nowadays, it is hard to distinguish what proportion of English names are really of English origin. The example of Smith has already been noted. In Co. Cavan the Smiths were originally McGowans or O’Gowan.

Many surnames are still found mainly in the area of origin, even with increased mobility and a gravitation towards the greater Dublin area. Moriaritys are mainly found in Co. Kerry, O’Driscolls and Riordans in Co. Cork.

The derivation of some Irish names can be fraught with difficulties and not as obvious as they appear. The surname Enright would appear to be derived from the Irish word inreachtach meaning lawful. But there is evidence to suggest that it is derived from the word indreacht meaning attack.

The origin of the name Ryan is more problematic. Experts differ as to its origin. It may be derived from an old Irish word for water or it could mean a person who marshals or puts order on things.

Taking all these factors into consideration we hope that after consulting these pages you have a better understanding of the origins of your surname.