Monessa
Feast: 4 September (not on the universal Roman calendar; kept in the Roman Martyrology or local calendars)
Who they were
Monessa, also called Moninne, Darerca, Blinne or Slaine, was an abbess of the Uí Nialláin clan in Ulster who founded the monastery of Killeavy on the slopes of Slieve Gullion around the end of the 5th or start of the 6th century. Early Irish martyrologies already attest her veneration by the 9th century, and tradition links her to St Patrick and to St Mac Cairthinn, bishop of Armagh, placing her at the heart of the evangelisation of Ulster.
Under her guidance Killeavy combined liturgical prayer, manual work, copying manuscripts and teaching, and drew vocations from beyond Ulster; several of her disciples went on to found their own communities. She died on 4 September, traditionally around 518, and is honoured as a secondary patroness of Ireland, invoked against illness.
The miracles
There was never a formal cause: she has been honoured as a saint since before the Church's formal processes began.
Why that counted as sanctity
Irish abbess who founded the monastery of Killeavy in Ulster around 500 and is honoured as a secondary patroness of Ireland; feast 4 September.
- Santi, beati e testimoni (santiebeati.it) - Santa Monessa d'Irlanda
- Wikidata Q4301698 — dates, feast day and identifiers (CC0)
Checked against the sources listed on 22 September 2026. Corrections welcome.