At this time whether Clooney was the only parish church in Glendermott, is impossible to say, but it can hardly have been so because less than 100 years later it was so dilapidated that Nicholas Weston, ‘An English bishop, pulled it down to use its material for building his palace at Bunseantuinne. This demolition, according to O’Donnell, had been prophesied by St. Columba (the founder of the church). The ruins of Clooney, probably the oldest ecclesiastical building extant around Derry, still exist in St. Columb’s Park.
Glendermott parish was in a peculiar position in that the Dean of Derry was automatically vicar and rector or parish priest, and in that he had to appoint another to perform the duties of the office, As vicar and rector, the Dean took two thirds of the tithes, the dues collected on the produce of the parishioners’ farms and, out of this he paid the procurator.
It appears probable that the Church at Clooney while within the parish had some sort of independence in the sense that the priest in charge had not the status of an assistant as had the priest at Clondermott.
Despite the tribal feuds and petty wars that were waged intermittently through the 15th and 16th centuries there must have been a lively faith and an earnest practice of religion in Glendermott during that age. The diocese was blessed with three extraordinary bishops. Donald O’Fallon, who ruled from 1485 to 1500, Rory O’Donnell from 1520 until 1551, and the great Redmund O’Gallagher, who took possession of the see in 1569 and was killed in 1602 the fact that there were so few notices of Derry in the various roman and metropolitan documents of the time shows that religion was being practised in a normal way, and the occasional entry indicating some irregularity is obviously something that shocked the faithful by its very rarity.
The spiritual life of the faithful was regulated in much the same way as it is today. In addition to attending mass on Sundays and holidays, the people were expected as we read in the statutes of the Synod of Cashel, to be present at Matins also. Two priests seemed to have been considered the minimum number to have in a parish, and in Glendermott there were in this early modern period probably four engaged in the pastoral ministry. Every church had to have three images or statues, one of the Crucifixion, another of the Blessed Virgin Mary, and the third of the patron saint of the place. The priest was responsible for the upkeep of the chancel, the laity for the body of the church, and there were strict regulations about keeping the graveyard in decent order.
Finally, the English were convinced that they were getting nowhere in their attempt to advance up the country, and it was then that they finally decided to take the Irish from the rear by once again occupying Derry. This they did in April 1600, and from henceforth the Bishop was in imminent peril. Tradition has it that he dressed as a herdsman and dwelt on the slopes of Corrody Hill. Whilst accounts differ, the De Praesulibus account narrates he was seized at Cumalia, an out of the way hamlet, a mile from Derry on the way to Strabane. He had hid in a bog, but due to his enfeebled old age he slipped into a house at the dead of night.
On approach of the enemy all but the Bishop took to flight, so he hid in sheaves of corn. However, the Bishop’s voice was overheard and was mangled with many a wound that left him lifeless. And so, ended a chapter in the history of the parish, and indeed of the diocese. For many a long year Derry was to be without a bishop, and in the trials that were to fall upon our people, none would be more severely tested than the Catholics of Glendermott. Kinsale was the last episode in the Irish war: but the occupation of Derry in 1600 had already made inevitable the defeat of O’Neill and his allies.