St. Ninnidh was a grandson of the High King Laoire, who was born in Donegal and from an early age it was seen that he was interested in religious matters. St. Ninnidh preached along the South shore of Lough Erne making the island of Inishmacsaint (island of plain Sorrell) his headquarters around 523AD. He likely journeyed up and down the Southern portion of Lower Lough Erne in a hollowed-out boat, coming ashore and making his way inland to meet people and spread the gospel.
The Parish in the early 18th century had four churches: Finner (Bundoran), Slavin, Derrygonnelly and the mother church at Drumenagh (Church Hill), which was constituted the parish church in 1710 when the Rev. John Smyth was Rector. Records tell us that John Smyth was of “Wheathill” and was ordered to supply “a font and surplice and nominate a curate for the district near Ballyshannon.
The present church at Benmore was erected in 1831 on the site of a house owned by a Robert Dundas, Mr. Dundas was given a house and land in another part of the Ely Estate in lieu. The church was consecrated for public worship on 31et August 1831 by the Rt. Rev. Robert Ponsoby Tottenham, Bishop of Clogher and who was also the father of Dean George Totttenham (his tenth son) who was later to become rector of the parish from 1865 to 1904.
At that time, Inishmacsaint Parish also included two chapels of ease called Slavin and Finner. This was indeed a very large parish which stretched from Derrygonnelly to Bundoran and necessitated two curates. In 1844 three curates were attached to the parish. The average attendance at Inishmacsaint was 250 whilst Slavin and Finner could seat 80 people each with an average attendance of 40 at Slavin and 25 at Finner.
To-day the parish has a population of 105 families but does not include Slavin and Finner. Slavin now comes under the grouped parishes of Garrison, Slavin, Belleek and Kiltyclogher and Finner comes under the Diocese of Derry and Raphoe.