Rev. Alban Butler (171173). Volume IV: April. The Lives of the Saints. 1866.
St. Celsus, Bishop in Ireland
[In Irish, Ceallach.] HE was archbishop of Armagh and is commemorated in the Roman Martyrology on this day. He died on the 1st of April, in 1129, at Ard-Patrick, (that is, Patricks Mount,) in Munster. See the life of St. Malachy, his successor, and Sir James Ware.