Place names and the Ordnance Survey

The basic function of a placename is to establish identity and to assist communications. Placenames are a valuable part of our cultural inheritance.

The history of placenames in the Ordnance Survey began in November 1824 when the first survey of Ireland by the British Ordnance Survey commenced. The survey was at a scale of 6 inches to one mile.

At that time, local taxes were based on the Valuation of Townland units. Detailed mapping of townlands was required to make the tax system more equitable. There are over 51,000 townlands in the Republic of Ireland and each one is named. In this extract from the 6 inch plan Donegal 004-01, the townlands are outlined in red.


Special instructions, concerning the treatment of Placenames, were issued by the officer in charge of the survey Lt. Col. Thomas Colby.

  • The persons employed on the survey are to endeavour to obtain the correct orthography of the names of places diligently consulting the best authorities within their reach.
  • The name of each place is to be inserted as it is commonly spelt, in the first column of the name book; and the various modes of spelling it used in books, writings &c., are to be inserted in the second column, with the authority placed in the third column opposite to each.
  • The situation of the place is to be recorded in a popular manner in the fourth column of the namebook.
  • A short description of the place and any other remarkable circumstances relating to it are to be inserted.

This data was recorded in Namebooks which are now stored in the National Archive.

From 1830, Irish civilians were employed by the survey to collect and examine the evidence for the purpose of deciding a suitable English language spelling for each name which had not already an accepted standardised English orthographic form.
Generally speaking, the spelling in English of the names of towns and of some physical features had already been standardized. Most of the work still to be done was related to the numerous townlands [over 51,000][/over].

The vast majority of the names originated in the Irish language and the standardised forms were to be anglicisations.

There are many examples, here are a few of the more common ones:
Baile_________ became Bally__________,
Cill___________ became Kil____________,
Dún_________ became Dun___________ or Down__________. etc.,

The most famous of the researchers was John O Donovan from Kilkenny. Others involved were Eugene Curry from Clare and Thomas O Connor from Monaghan. The rise of Nationalism in the 1900’s led to renewed interest in the Irish language. The Gaelic League published a book in 1905,written by Seosamh Laoide. The book was called Post-Sheanchas and it gave the Irish language form of the names of the Post Offices in Ireland.

Around the same time Dublin Corporation began erecting bilingual street nameplates.

In 1946 An Coimisiún Logainmneacha was established.

The Placenames Branch of the Ordnance Survey was established with the purpose of researching the placenames of Ireland in order to provide authoritative Irish language forms of those names for both official use and for use by the general public. The research was focused on the names of the administrative units and the physical features.

Many sources were available when attempting to ascertain the original Irish forms of Placenames.

These sources include surviving native materials written in Irish and Latin between the 7th and 19th Centuries.

However, the majority of Irish placenames are found only in anglicised versions.

These include:

  • Rolls and Deeds relating to the Anglo-Norman period of the 13th and 14th centuries.
  • Inquisitions and Surveys which detail the seizures and land grants of the 16th and 17th centuries.
  • The Deeds and Estate Maps of the 18th century.
  • Documents relating to the first Ordnance Survey of Ireland, particularly the Namebooks and the Irish forms recorded by John O Donovan and his colleagues.

The Placenames branch provided Irish placename forms for a number of the Ordnance Survey’s maps. In the 1970’s , it was decided, as far as possible, that all the administrative names, townlands, baronies and electoral districts would be bilingual. Larger Geographical features were also to be bilingual.

The following extract from the OSi Act 2001 describes administrative units and how they evolved.

Extract from Sheet 3175-A showing the names of the E.D. and the townland bilingually.

Extract from 1:50,000 Discovery series showing the official English language version and official Irish language version of the mountain name.

Extract from Road Atlas of Ireland, 4th Edition, Page 34 showing the official English language version and official Irish language version of some town names.

Information extracted from Ordnance Survey In Ireland and The Placenames of Ireland in the Third Millennium.

These publications will help with any research.

Gasaitéar na hÉireann /Gazetteer of Ireland

  • 1989
  • Lists bilingually 3500 approx, of the most widely used placenames in Ireland.
  • Includes a National Grid Reference [ING][/ING]
  • A guide to the pronunciation of the Irish version of the name

Logainmneacha na hÉireann

  • 1990
  • will present all the documentry evidence for each form of the name.
  • Produced on a county basis

Liostaí Logainmneacha

  • 1992
  • Bilingual lists of the official Irish and English place names of all permanent administrative units in each county
  • includes townlands, civil parishes & baronies.
  • One book per county.

There is also a Gazeteer in The Complete Road Atlas of Ireland.