On the north bank of the Quoile River, Inch Abbey was founded by John de Courcy in atonement for his destruction of Erenagah Abbey.
In the early 12th century an Augustinian House was established here. In 1183 John De Courcy invited Benedictine monks from St Wenburghs in Chester to come and establish a monastery here. Parts of this present building were part of that original monastery. With the dissolution of the monasteries in 1538 the monks left and the building gradually fell into ruin. In 1609 James I granted a Charter to establish a Dean and Chapter here and although still a ruined site, bishops were consecrated within the walls.
Towards the end of the 18th century Dean Annesley, along with Willis Hill (of Hillsborough) and many of the notable families of County Down raised funds to completely restore this building. Over the years, there have been many periods when the Chapter Book records that the Cathedral was closed for repairs. But none was as far reaching as the recent renovations which took place in 1986/7. Attacks of rot were so extensive that the Cathedral Board, acting on professional advice decided to remove almost the entire interior plaster walls and vaulting.
What the visitor sees now is an almost entirely new interior, a replica of that which it replaced.