Máel Muire Ó Lachtáin
Máel Muire Ó Lachtáin was Dean of Tuam from 1230 and then the fourth Archbishop of Tuam from 1235 to 1249. The History of the Popes describes him as:

Dean of Tuam, having been elected by the Chapter, was accepted by the Pope, and afterward received confirmation from the King (Henry III of England). The Four Masters seem to intimate that he was consecrated in England. He is said to have been an eminent canonist ... He undertook a pilgrimage to Jerusalem and wrote an account of it. ... He died at the town of Athlone, about Christmas, in the year 1249. References

 https://archive.org/stream/fastiecclesiaehi04cottuoft#page/n33/mode/2up
 Annals of the Four Masters at CELT
 https://archive.org/stream/fastiecclesiaehi04cottuoft#page/n17/mode/2up

Archbishops of Tuam
Medieval Gaels from Ireland
Pilgrimage accounts
Medieval Irish writers
Christian clergy from County Galway
13th-century Roman Catholic archbishops in Ireland
1249 deaths
Deans of Tuam
13th-century writers
Year of birth unknown
Irish expatriates in England