Lough Derg, Ireland. This celebrated sanctuary in Donegal, in the Diocese of Clogher, dates from the days of St. Patrick, but it is also known as the Lough Derg pilgrimage, so named from Lough Derg, a sheet of water covering 2200 acres, about thirteen miles in circumference 450 feet above sea level, on which are eleven islands, the principal of which are Saints Island and Station Island. The sanctuary lands on Saint Island were known in the Middle Ages as Termon Dabheoc (from the sixth-century St. Dabheoc who presided over the retreat), and were subsequently called Termon Magrath from the family of Magrath, who were coarbs or stewards of the place from 1290. St. Patrick's connection with the purgatory which bears his name is not only a constant tradition, but is supported by historical evidence, and admitted by the Bollandists. In 1130 or 1134, the Canons Regular of St. Augustine were given charge of Lough Derg—it being constituted a dependent priory on the Abbey of Sts. Peter and Paul, Armagh. Its fame became European after the knight Owen's visit in 1150, although it had been previously described in 1120 by David, the Irish rector of Wurzburg. Numerous accounts of foreign pilgrimages to St. Patrick's Purgatory are chronicled during the thirteenth, fourteenth, and fifteenth centuries, including the vision related in the "Legenda Aurea", printed in 1482.

In 1470, Thomas, Abbot of Armagh, got the priory in commendam, and in 1479 the community had almost died out, the revenues being farmed by Neill Magrath. Pope Alexander VI ordered the cave to be closed on Saints Island, the papal decree was executed on St. Patrick's Day, 1497. A few years later, in 1502, the station was transferred to Station Island, where the Purgatory had originally existed. The cave was visited by a French knight in 1516, and by the papal nuncio, Chiericati, in 1517. Chiericati gives an interesting account of his visit, and relates that there were three Austin Canons in the priory. Though formally suppressed by the English Government in 1632, the lay owner permitted the Austin Canons to resume their old priory, and in 1660 we find Rev. Dr. O'Clery as prior, whose successor was Father Art Maccullen (1672-1710). The Franciscan Friars were given charge of the Purgatory in 1710, but did not acquire a permanent residence on the Island till 1763, at which date they built a friary and an oratory dedicated to St. Mary of the Angels. In 1780 St. Patrick's Church was built, and was subsequently remodeled. From 1785 the priory has been governed by secular priests appointed by the Bishop of Clogher. In 1813 St. Mary's Church was rebuilt, but it was replaced by the present Gothic edifice in 1870, and a substantial hospice was opened in 1882. The number of pilgrims from 1871 to 1911 has been about 3000 annually, and the station season lasts from June to 15 August. The station or pilgrimage lasts three days, and the penitential exercises, though not so severe as in the days of faith, are austere in a high degree, and are productive of lasting spiritual blessings.

Messingham, Florilegium Insuix Sanctorum (Paris, 1624); Ware, Antiquities of Ireland (London, 1654); O'Brullaghan, The Pilgrimage of Lough Derg (Belfast, 1726); O'Connor, St. Patrick's Purgatory (new ed., Dublin, 1895); Healy, Life and Writings of St. Patrick (Dublin, 1905).

W. H. Grattan-Flood.