The majority of Irish placenames have their origins in the Irish language and accordingly constitute a very considerable body of valuable linguistic data. Most names in an English language context are written in an Anglicized orthography that is often a fairly thinly-disguised version of the original Irish form. Other languages represented in the body of Irish toponymy include Latin, Norse, Norman French, and, of course, English, while there is a handful of names that may arguably be of pre-Celtic origin. Placenames of such diverse origins reflect the complexity of Ireland’s linguistic history. Some names that are at least partly Latin in origin date from the early Christian centuries, while from the Viking era, the ninth and tenth centuries, we have (in contrast to the Highlands and Islands of northern and western Scotland) a remarkably small number of Norse names, almost all of them on or near the eastern and southern coasts. Comparatively few names of indisputably Norman-French origin survive. As one might expect, English has had a significant impact on Irish nomenclature, although purely English names are considerably less numerous than Anglicized or hybrid English-Gaelic name-forms.
The body of Irish toponymy may be likened to a pyramid. Starting at the top, there is the name of the island (from the prehistoric form Iuerne through Eriu in Old Irish to Eire in Modern Irish); below this are, in turn, the early bifold division of the island into Leth Cuinn and Leth Moga ("Conn’s half" and "Mug’s half," respectively); the "fifths" or provinces whose roots go back to prehistoric times; the counties, 32 of which were established between the early post-Norman period (c. a.d. 1200) and the beginning of the seventeenth century; the baronies, of which there are 324, some of them representing ancient Gaelic divisions; the civil parishes, some 2420, reflecting medieval ecclesiastical parishes that may have been established at the same time as the dioceses in the twelfth century, although many have roots going back much further; and finally, at the bottom of the pyramid, is the smallest administrative unit, that peculiarly Irish division, the townland, of which there are more than 60,000, ranging in area from less than one acre to more than 7,000 acres. Below this level is a vast body of microtoponymy, much of which has never been recorded, let alone printed on maps, and is therefore in imminent danger of being lost forever; such names are most numerous in areas in which Irish is, or was until recently, spoken.
A few dozen Irish placenames can be traced back almost two millennia to the work of the Alexandrian geographer Ptolemy, although identifying many of these with certainty is problematical. Many others occur in a wide range of documents from early to late medieval times, but the majority of names are attested in documents from the later sixteenth century onwards. The corpus of Irish placenames reflects such things as natural features, flora and fauna, land divisions, settlement patterns (secular and ecclesiastical), ways of life and death, land clearance and cultivation, historical events, and religious and mythological matters, as well as land ownership (through inclusion of personal and family names).
The scholarly study of Irish placenames has its roots in the work of the Ordnance Survey, established in Ireland in 1824. The Survey’s first superintendent, Thomas Larcom, had the foresight to employ the young Kilkenny scholar John O’Donovan to assist with processing the thousands of placenames that any scheme to map the entire country would encounter. O’Donovan— later joined in the Survey’s Topographical Department by George Petrie, Eugene O’Curry and others—went on to become the greatest Irish scholar of the nineteenth century. Most of his early scholarly work was related to the collection and interpretation of tens of thousands of placenames, many of them to be found only on the lips of native speakers of Irish, never having previously been written down. O’Donovan’s pioneering work on a great range of sources, most of them lying unpublished in medieval manuscripts, led to his masterly editions of various Irish texts, most notably the Annals of the Four Masters.
Further valuable work on Irish placenames— though largely based on O’Donovan’s researches— was done by Patrick Weston Joyce, while early in the twentieth century Edmund Hogan, SJ, produced his remarkable Onomasticon Goedelicum, a dictionary of placenames culled mainly from medieval sources (many of them still in manuscript). Other noted twentieth-century contributors to Irish toponymical studies included Canon Patrick Power on the placenames of Decies, County Waterford, and of east Cork, Padraig O Siochfhradha ("An Seabhac") on those of the barony of Corkaguiny, County Kerry, Fr. Paul Walsh on County Westmeath, and Liam Price on the placenames of County Wicklow.
In 1946 the Irish government established the Irish Placenames Commission to further scholarly research into Irish placenames, in order to furnish authoritative Irish forms for public use. Work commenced on the names of more than 3,000 postal towns throughout Ireland, resulting, eventually, in the book Ainmneacha Gaeilge na mBailte Poist (1969)—later incorporated in the Gazetteer of Ireland/Gasaitear na hEireann (1989). In 1955, the Commission’s research functions were transferred to the newly established Placenames’ Branch of the Ordnance Survey, while the Commission retained an overseeing and advisory role in relation to the Branch’s activity. The Branch commenced work in the early 1970s on the names of townlands, on a county-by-county basis. This led to a book on the placenames of County Limerick (1991) and bilingual lists of the townland and other names of six counties (Limerick, Louth, Waterford, Kilkenny, Monaghan, and Offaly—with Dublin, Tipperary, and Galway soon to follow). In 1999 the Placenames’ Branch was detached from the Ordnance Survey; it now operates under the Department of Community, Rural and Gaeltacht Affairs. Meanwhile, in 1987, with British government funding, the Northern Ireland Place-Name Project was established in Queen’s University Belfast to undertake similar work to that of the Placenames’ Branch in relation to the six counties of Northern Ireland. Part of the fruits of the Project’s researches was published in seven substantial volumes before official funding ceased in 1997. Since then, with alternative (but much reduced) funding, a smaller staff has continued the research and produced three further volumes. Valuable work is also being done on the corpus of earlier Irish placenames by the LOCUS Project which was established in 1996, with a grant from Toyota Ireland, Ltd., in the Department of Early and Medieval Irish, University College, Cork. Representing the initial instalment of a detailed revision of Hogan’s Onomasticon, the first fascicle of the new Historical Dictionary of Gaelic Placenames appeared in 2003.
