Iarlaithe mac Loga

Saint Iarlaithe (Jarlath)
Ruins of Teampall Jarlath, a 13th-century parish church in Tuam, dedicated to Iarlaithe
Died	26 December, c. 540
Venerated in	Roman Catholic Church Eastern Orthodox Church
Feast	6 June (currently) 25 or 26 December (earlier)
Patronage	Archdiocese of Tuam

Saint Iarlaithe mac Loga, also known as Jarlath (fl. 6th century), was an Irish priest and scholar from Connacht, remembered as the founder of the monastic School of Tuam and patron saint of the Archdiocese of Tuam. No medieval Life for Iarlaithe is extant, but sources for his life and cult include genealogies, martyrologies, the Irish Lives of St Brendan of Clonfert and a biography compiled by John Colgan in the 17th century.

The Irish genealogies record the existence of two saints named Iarlaithe: Iarlaithe son of Lugh (Iarlaithe m. Loga), founder of Tuam, and Iarlaithe son of Trian (Iarlaithe m. Trena), bishop of Armagh. Iarlaithe of Tuam is said to have belonged to the Conmhaícne, who ruled over the greater part of what would become the parish of Tuam. The other saint is said to have belonged to the Dál Fiatach in east Ulster. He is identified as the third Bishop of Armagh, that is after Patrick's heir Benignus and the Annals of Ulster and Innisfallen record his death in the year 481.

In the two Irish Lives of St Brendan, possibly of the 12th century, Iarlaithe is called a son of Lug, son of Trén, son of Fiacc, son of Mochta, and the First Life in the Book of Lismore continues the pedigree by calling Mochta a son of Bresal, son of Siracht, son of Fiacha the Fair. Both Lives substitute Imchada for Mochta and on this basis, Séamus Mac Mathúna argues that they go back to an original which conflates the genealogy of Iarlaithe mac Loga with that of his namesake in Armagh.Dónall Mac Giolla Easpaig suggests, however, that the saints could refer to one and the same person:

[...] both are given as the third bishop of Armagh [...] placename evidence from the Tuam area would tend to corroborate [this] view [...] the evidence suggests that there was a strong Patrician and, consequently, a strong Armagh influence in the Tuam area from the earliest Christian period [...] the fact that Iarlaithe was a bishop like Benignus of Kilbennan and Felartus of Donaghpatrick, would further indicate that Tuam [...] would have predated Brendan of Clonfert by almost a century.