Background
He was born in Droles, Lisbellaw, County Fermanagh.
He was born in Droles, Lisbellaw, County Fermanagh.
Mulligan died on 21 January 1990, aged 78 years and is buried in the grounds of Street Macartan"s cathedral, Monaghan. Mulligan was ordained a priest of the Diocese of Clogher in 1937. He was Diocesan Secretary for a period and also a teacher in Street Macartan"s College, Monaghan, and Street Tiarnach"s School in Clones.
He became the first President of Saint Michael"s College (Enniskillen) in 1957, retiring from that position in the summer of 1966.
In that year, he was appointed to the position of Archdeacon of Clogher and Parish Priest of Carrickmacross. He was appointed Bishop of Clogher on November 28, 1969 and ordained two months later on January 18, 1970.
He was preceded by Eugene O"Callaghan who retired as bishop on November 28, 1969. During his term as bishop he oversaw the implementation within the diocese of many of the changes brought about by the Second Vatican Council.
During his term three new churches and several schools were built in the diocese.
He was a local historian and Irish language expert. He was succeeded by Joseph Duffy, and during his retirement wrote a short History of the Diocese of Clogher and several articles for local historical journals as well as serving several terms as President of the Clogher Historical Society.