Grianan of Aileach Ring Fort

This is the Grianan of Aileach in County Donegal, Ireland. It is also called "Grianán Ailigh". The fort was closed for construction on the day that we were there. An online encyclopedia entry about this ring fort is at We photographed another ring fort in County Donegal in 2005 and a ring fort in County Kerry in 2007.

In The History of Ireland by Geoffrey Keating which is available online at, Geoffrey Keating uses Ptolemy (Claudius Ptolemaeus, ca. 90 ca. 168 AD) as a source. The Geographia written by Ptolemy, mentions a "Regia" that 18th century historians such as Keating interpreted as referring to the Grianan of Aileach.

A tall curved stone wall with an opening covered by a lintel stone.

The translation from Gaelic to English of the Annals of the Four Masters at University College, Cork has an account of the destruction of this ring fort by O'Brien in about the year 1101.

compiled by Myriam Priour, Stephen Beechinor
Funded by University College, Cork and Seoirse Ó Luasa, An Caifé Liteartha, An Daingean, who donated a copy of the Annals of the Four Masters to the CELT Project.


A great army was led by Muircheartach Ua Briain, King of Munster, with the men of Munster, Leinster, Osraighe, Meath, and Connaught, across Eas-Ruaidh, into Inis-Eoghain; and he plundered Inis-Eoghain, and burned many churches and many forts about Fathan-Mura, and about Ard-sratha; and he demolished Grianan-Oiligh, in revenge of Ceann-coradh, which had been razed and demolished by Domhnall Ua Lochlainn some time before; and Muircheartach commanded his army to carry with them, from Oileach to Luimneach, a stone of the demolished building for every sack of provisions which they had. In commemoration of which was said:

  1. I never heard of the billeting of grit stones,
    Though I heard of the billeting of companies,
    Until the stones of Oileach were billeted
    On the horses of the king of the West.

Muircheartach after this went over Feartas-Camsa into Ulidia, and carried off the hostages of Ulidia; and he went the round of all Ireland in the space of a fortnight and a month, without battle, without attack, and he returned to his house by Slighe-Midhluachra. The expedition was called "The circuitous hosting."

500 years later, according to the Annals of the Four Masters, revenge was taken for the destruction of the fort. The spelling of the names had changed as the five centuries passed. That seems to me an exceptionally long time to hold a grudge.


The learned historian and poet, Mac Brody (Maoilin Oge), represented that it was in revenge of the demolition of Grianan Oiligh, formerly, by Murtough More, son of Turlough [son of Teige], son of Brian Boroimhe, that God, in consequence of the curse of Columbkille upon the O'Briens, had permitted Thomond to be totally plundered and devastated on this occasion by O'Donnell. This Maoilin Oge came to O'Donnell, to request of him the restoration of his cattle, which a party of the troops had carried off; and they were all given back to him; upon which Maoilin composed the following quatrain:

  1. It was destined that, in revenge of Oileach,
    O Hugh Roe! the Prophet announced,
    Thy troops should come to the land of Magh-Adhair;
    From the North the aid of all is sought.

The Annals of Ulster at also has an account of the destruction of this ring fort and also says that the year was 1101.

compiled by Pádraig Bambury, Stephen Beechinor
Funded by University College, Cork and
Professor Marianne McDonald via the CELT Project. CELT: Corpus of Electronic Texts: a project of University College Cork
College Road, Cork, Ireland
Distributed by CELT online at University College, Cork, Ireland.
Text ID Number: T100001A
Available with prior consent of the CELT project for purposes of academic research and teaching only.


An expedition was made by Muirchertach ua Briain and by Leth Moga into Connacht, and over Eas Ruaidh into Tír Eógain, and they razed Ailech and burned and outraged many churches also, including Fathain of Muru and Ard Sratha. They went thereafter over Fertas Camsa and burned Cúl Rathain and committed slaughter there. They afterwards took the hostages of the Ulaid. They went home over Slige Midluachra.

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