The diocese of Down was one of the twenty-four dioceses establish at the Synod of Rathbreasail in 1111 and comprised roughly the eastern half of County Down. For a brief period in the early 12th-century, Down was united with the see of Connor under Máel Máedóc Ua Morgair (Saint Malachy). who also became Archbishop of Armagh.[3]
On 29 July 1439, plans for a permanent union of the sees of Down and Connor were submitted to King Henry VI of England for his sanction. Exactly twelve months later, 29 July 1439, Pope Eugene IV issued a papal bull stating that Down and Connor were to be united on the death or resignation of either bishop.[3] On 29 May 1441, Archbishop Prene of Armagh sent a letter to Pope Eugene IV in which he writes about the crimes and excesses of Bishop John Sely of Down, one of which was that Sely was living openly with Lettice Thomas, a married woman, at Kilclief Castle.[4][5] Following receiving the letter, the pope deprived Bishop Sely of the see of Down at some date before November 1442, and thereby effecting the union of the two dioceses. John Fossade, who had been bishop of Connor since 1431, became the bishop of the united see of Down and Connor in late 1442. However, there was strong local opposition to the union, and Archbishop Prene's register shows that he also was for a time opposed to the union. There were three more bishops of Down were appointed before the two sees finally united.[3][6]
Máel Máedóc Ua Morgair or Malachias I; became bishop of Down and Connor in 1136, and Archbishop of Armagh in 1134; he resigned Armagh and Connor in 1136, but retained Down until his death on November 1148.
Formerly Archdeacon of Down; elected bishop before April 1258; received possession of the temporalities and consecrated after October 1258; translated to Cloyne 13 April 1265.
Thomas Liddel; elected before April 1258, but was rejected by King Henry III of England; elected again 1265 and consecrated after 5 July 1265; acted as a suffragan bishop in the diocese of Lincoln 1270; died before February 1277.
John of Ballyconingham; elected before 4 August 1328 and received possession of the temporalities on that date, however, the election was annulled by the pope, and was translated to Cork sometime before January 1329.
John Cely; formerly Prior of Down; appointed 28 July 1413; deprived before November 1442; died before 26 April 1445.
In 1442, the sees of Down and Connor were united by Pope Eugene IV, and John Fossade, who had been bishop of Connor since 1431, became bishop of the united see of Down and Connor. However, due to strong opposition three more bishops of Down were appointed.
Appointed 21 June 1451; acted as a suffragan bishop in the dioceses of Lichfield 1452, Worcester 1465–79, and Hereford 1479; resigned the see of Down before August 1453; died after 1479.
^ abcdFryde, E. B.; Greenway, D. E.; Porter, S.; Roy, I. (1986). Handbook of British Chronology (3rd ed.). Cambridge: Cambridge University Press. pp. 334–336, 347–348. ISBN0-521-56350-X.
^Kilclief Castle. Irish Antiquities. Retrieved on 25 August 2009.
^ abCotton, Henry (1849). The Succession of the Prelates and Members of the Cathedral Bodies of Ireland. Fasti ecclesiae Hiberniae. Vol. 3, The Province of Ulster. Dublin: Hodges and Smith. pp. 197–201.