Ailech, or the Grianan of Ailech, was the caput, or principal royal seat of the early medieval Northern Ui Neill kings of Cenel nEogain, until they moved their headquarters to Tulach Oc in the kingdom of Airgialla at the beginning of the eleventh century. The place-name Ailech was also used as the distinguishing sobriquet of the Northern Ui Neill dynasty. Ailech is popularly identified as a large multi-period fortification situated on Greenan Mountain at the southern end of the Inishowen Peninsula, County Donegal. However, Elagh, which is an Anglicized form of "Ailech," in nearby County Derry, could also have been the location of the historic Northern U Neill capital. The chronicles note the destruction of the Grianan of Ailech by the army of Muirchertach Ua Briain, king of Munster, in 1101. It was demolished in revenge for the destruction of the U Briain stronghold at Cenn Corad (Kincora), Killaloe, County Clare, which had been destroyed by Domnall Mac Lochlainn of the Northern U Neill in 1088.
Aerial view of Grianan of Ailech, Co. Donegal.
The reputed site of Ailech on Greenan Mountain commands extensive views over Lough Foyle and Lough Swilly, and its lofty location, combined with the fact that it can be seen for a considerable distance, suggests that it was as much to be viewed as to view from. It consists of a triple-ramparted hillfort at the center of which lies an early-medieval caiseal, or stone fort. In addition, there are the vestiges of a mound or tumulus of possible Neolithic or Bronze Age date, the site of a ceremonial road approaching the fortification, and a holy well. The three earthen ramparts that enclose and predate the central caiseal appear to constitute a hillfort of the Late Bronze Age or Iron Age period. The caiseal was an early medieval addition to the hillfort and its construction perhaps signified the appropriation of Ailech as the headquarters of the Northern U Neill in the sixth century. Its present-day form is the result of significant rebuilding undertaken in the 1870s by Dr. Bernard, the Bishop of Derry. The caiseal is a very fine drystone structure with an elegant external batter. It has an internal diameter of circa 24 meters and rises internally in three terraces, with each tier accessible by means of inset staircases. The walls are about 4 meters thick and rise to a height of 5 meters. An entrance passageway, which is roofed with stone lintels, leads from the east into the interior. Additional stone passages run into the fort from the south and the northeast. Outside the caiseal, at a distance of 25 meters, one meets with the inner rampart of the hillfort, which survives as a heather-clad earthen bank. A low cairn of stones, possibly representing the mound or "tumulus" that George Petrie noted on his plan of Ailech (1835), is situated midway between the inner and middle ramparts of the hillfort. Both of these ramparts survive as quite eroded features that follow the contours of Greenan Mountain. A holy well dedicated to St. Patrick lies on the south side between the middle and external banks of the hillfort. Parallel breaches in the three ramparts of the hillfort, at the east, and a corresponding entrance in the caiseal wall, indicate the former presence of a ceremonial roadway that was apparently lined by stone settings, leading into the heart of the site. The road ran between two upstanding ledges of rock as it approached the summit of Greenan Mountain. The appropriation of such a multi-period site as a royal residence and as a place of king-making would have been in keeping with the typical exercise of royal authority and royal display of power by early-medieval Gaelic ruling families.
Ailech is the subject of three dindshenchas poems that account for the origin of the name, the deeds of the legendary heroes associated with it, and the blessing of the site by St. Patrick. According to the text Vita Tripartita, compiled circa 900, Patrick went to Ailech and blessed the fort, and left his flagstone (lecc) there, and prophesied that kings and ordained persons out of Ailech would have supremacy over Ireland. The flagstone was subsequently called Lecc Phatraic, and it was upon this that future kings of the Northern U Neill were to be inaugurated at Grianan of Ailech. A local tradition in Derry identifies Lecc Phatraic with "St. Columb’s Stone," a large flagstone engraved with two shod footprints that lies in the garden of Belmont House near the city of Derry. This identification, however, cannot be supported.
The expansionist policy of the Northern U Neill saw them encroaching on the territory of the Airgialla as early as the tenth century. They specifically targeted Tulach Oc in Airgialla, which was colonized between 900 and 1000 by the Cenel mBinnig, a branch of the Ailech dynasty. By 1000 the ruling branch of the Cenel nEogain had established their royal headquarters at Tulach Oc. They had apparently set their sights on the kingdom of Airgialla as early as the ninth century. Their first success came in 827 when Niall Caille defeated the combined forces of Airgialla and Ulaid at the battle of Leth Cam. In the aftermath of Leth Cam the chronicles for this period reflect the hold that the Cenel nEogain had over Airgialla. The attraction of Tulach Oc for the kings of Ailech lay in the probability that it was the traditional inauguration site of the kings of Airgialla. To gain control of it would have struck at the very core and source of the kingship of Airgialla. That Tulach Oc was chosen as the preeminent inauguration place of CenelnEogain in preference to Ailech or Armagh is evidence enough of the political importance attached to it. The first king of Ailech to be inaugurated there, and in a ceremony presided over by an ecclesiastic, was possibly Aed Ua Neill. He was installed as king of Cenel nEogain by Muirecan, comarba of Patrick, "in the presence of Patrick’s community," while Muirecan was in Tir Eogain on visitation in 993.
