Fr Peadar Mac Suibhne was born as Peter Swayne in 1896, near Ballon, Co. Carlow. He was educated at Knockbeg College, Clonliffe College, University College Dublin and Carlow College (1916-1920), and was ordained in 1920 for the Diocese of Kildare & Leighlin. Fr Mac Suibhne joined the staff of Knockbeg College (1920-1949), including a period as Rector (1927-1949). He then served as parish priest, Suncroft (1949-1951) and Kildare (1951- 1970), both Co. Kildare. He retired to Carlow College in 1970, where he worked on the College archives.
Fr Mac Suibhne was a keen historian and wrote or edited a number of books, including a five-volume work on the etters of Paul Cardinal Cullen, Archbishop of Dublin (1803-
1878); parish histories of Killeshin/Graiguecullen, Clonegal, Ballon and Rathangan; the 1798 Rebellion in Carlow and Kildare; St Brigid; and various works relating to Carlow College and Knockbeg College.