His older sister Mary (McCall) became the first President of the Apostolic Work in 1924 indicating the faith and commitment of his wider family where there were others vocations to religious life.[2] While his mother was a sister of the late Dr Richard Marner, who served as President of St. Malachy's College from 1866 – 1876 and then Parish Priest of Kilkeel until his death in 1906.[3]
His first pastoral appointment was a summer curacy in Glenavy parish in July 1907 and on 1 September that year he was transferred to St Malachy's College where he taught both English Literature and Latin and served as Dean of Discipline.
In the 1930s he was a champion of Catholic rights especially after the anti-Catholic riots of 1935. He claimed that almost 400 Catholic families, totally nearly 1600 people had been driven from their homes. Dr. Mageean succeeded in getting the anti-Catholic nature of much of Northern Ireland life raised in the House of Commons at Westminster but his efforts came to naught and he resigned himself to a long period of sterility as prime ecclesiastical leader of demoralised Northern Irish Catholics.[5]
A flavour of the struggles Bishop Mageean faced are considered in Jonathan Bardon's magisterial work on this history of Ulster.[6] Bishop Mageean often used his Lenten Pastoral letter to address issues of wider social and political concern e.g. his 1938 letter on Partition and the persecution of Catholics in Northern Ireland.[7]
