Saint Celsus of Armagh

Also known as

  • Ceillach
  • Cellach Mac Aodh
  • Cellach Mc Aedh
  • Cellach of Armagh



Benedictine monk. May have been a monk at Glastonbury. Teacher at Oxford, England. Last hereditary archbishop of Armagh, Ireland in 1106. Built a reputation as a reformer and able administrator. Travelled throughout Ireland, preaching reform and ensuring discipline. Helped preside at the Synod of Rath Bresail in 1111, which helped align the Irish church administration with the rest of Europe. Rebuilt the Armagh cathedral. Peacemaker between warring Irish kings and chieftains. Worked with, and ordained his friend Saint Malachy O’More. From his deathbed, he appointed Malachy as Archbishop of Armagh, ending the tradition of hereditary succession to the see.



Additional Information

MLA Citation

  • “Saint Celsus of Armagh“. CatholicSaints.Info. 31 March 2017. Web. 16 December 2018. <>