Foundation c. 454 AD
St Macartan and the First See
Aedh Mac Cairthinn - latinised as Macartan - was born in Ulster and went south to hear Patrick preach, meeting him first at Drumlease near Dromahair in County Leitrim. Baptised and taken on as a companion, he became known as Patrick's "strong man" (treinfhear) for his physical strength and his loyalty. Patrick appointed him first Bishop of Clogher, placing him on a hill in south Tyrone that was already a site of royal and spiritual significance. According to tradition he died around 505 AD, having established the monastery that would become the longest-running episcopal see in Ulster. His feast day is 24 March. The Diocese of Clogher celebrates his memory still.
A golden stone and a pagan oracle
The Clogh-Oir
The name Clogher derives from An Clochar - the stone place - and specifically from the Clogh-Oir, the golden stone. This was a pagan oracle stone, said to have been covered in gold and consulted by the kings of Ulster, among them Concobar MacNessa, High King of Ulster. The Clogh-Oir was counted as one of the three great sacred stones of Ireland, alongside the Stone of Destiny and the Crom Cruach. Early Christian tradition holds that Macartan destroyed or neutralised the oracle stone when he established the see - a standard act of supersession in the conversion of Ireland. What is less standard is that a carved stone still sits inside the cathedral today, identified by some antiquarians as the original. Whether or not that is so, the hill at Clogher carries the older name.
Synod of Rathbreasail, 1111
The Diocese Across Sixteen Centuries
The monastic church at Clogher was organised into a formal diocese at the Synod of Rathbreasail in 1111 - part of the broader reform of the Irish church under the influence of the continental model. The Diocese of Clogher was defined as the see for the Kingdom of Uí Chremthainn, covering a broad stretch of south-west Ulster. After the Reformation, Henry VIII confiscated the cathedral for the Church of Ireland; the Roman Catholic bishops of Clogher continued in a precarious existence through the penal period, holding the ancient title without a seat. A decision was made in 1851 to move the Catholic episcopal presence to the larger town of Monaghan, where the RC cathedral now stands. The Church of Ireland diocese remains based in Clogher, with its cathedral on the original fifth-century hill. In 2005 the Church of Ireland Diocese of Clogher was united with Armagh; the title survives.