Donnán (d. 615) of Eigg, missionary and martyr in Scotland, was born (according to tradition) in north-eastern Ireland; he trained under Finnian (qv) of Movilla, and came as a missionary to Scotland sometime before 590. He began his work in the Rinns of Galloway and went from there to the southern Picts in Ayrshire. A story is related in the twelfth-century notes to the Martyrology of Óengus (qv) (fl. c.830) that he met Colum Cille (qv) somewhere on the mainland of Scotland and asked him to become his anamchara (spiritual adviser). Colum Cille refused, prophesying that Donnán and his companions would soon suffer the ‘red martyrdom’ of violent death. Donnán's mission to north-western Scotland was quite independent of, but contemporary with, Colum Cille's mission to the south and west; this vignette may be a metaphor for their independent or rival missionary enterprises.
The location of Donnán's foundations suggests that he came from Candida Casa, the monastery of St Ninian at Whithorn in Galloway, and that he followed Ninian's missionary track, many of his foundations being adjacent to those of that saint. Donnán later set up a church at Suisgill (Kildonan, Sutherland), which he left to establish a settlement on the island of Eigg. An Irish tradition found in the Book of Leinster and other sources relates that Donnán and his companions had settled on land held ‘by the queen of the country's sheep’, who so resented their occupancy of it that she asked some Pictish or Frisian sea-pirates to raid the island and kill them. The pirates landed on the island as the monks were at prayer on Easter Saturday night/Sunday morning (in nocte Paschae) 18 April 615 (the annalistic data in AU, Ann. Tig., Chron. Scot., and Ann. Inisf. – ‘xv [recte xii] kl. Maii’ – agree with a Paschal date of 18 April, which occurred in 615). Donnán and his community asked to be allowed to finish their service; all then entered the refectory, which, according to some accounts, was set on fire. The number of those martyred is variously given as fifty-two or fifty-four. It has been plausibly suggested that the destruction of the mission was partly due to fear of Gaelic expansion into Pictish territory.
Donnán's settlement on Eigg is still attested by placenames and some fragments of ecclesiastical structures. The names of some of his fellow missionaries are also preserved in the area in placenames and church dedications. The slaughter is noted in several of the Irish annals and in all of the Irish and Scottish martyrologies, including the Aberdeen Breviary, but, significantly, not in the ‘Vita Columbae’ of Adomnán (qv).