Ecgberht (c.638–729), an Englishman of noble birth, moved to Ireland, ‘either for the sake of religious studies or to live a more contemplative life’, according to Bede. His departure for Ireland can be assigned to the period when Bishops Fínán (qv) (652–61) or Colmán (qv) (661–4) were abbots of Lindisfarne. He and his companion, Aethelhun, entered the monastery of Ráith Melsigi (Clonmelsh, Co. Carlow). He was in Ireland when the plague of 664–5 struck; he swore that if he were spared he would never return to his native land, but would remain in physical and spiritual exile.
It had been Ecgberht's intention to conduct a mission to the continental Germanic peoples and to win them over to the Roman observance, but it fell to the lot of his fellow countryman Willibrord (qv), also resident in Ireland, to undertake that great work at the insistence of his older compatriot. Ecgberht, Bede tells us, was dissuaded from this intention by a fellow monk of the Ráith Melsigi community, formerly from Melrose in Scotland, who related to him two dreams in which Boisil (qv) (d. c.660), prior of Melrose, had been told to warn Ecgberht against undertaking the mission. Although Bede dates these events to 690, two years before the Frisian mission undertaken by Willibrord, it is more likely that they occurred closer to the time of Ecgberht's arrival on Iona.
Ecgberht did not spend all of his long life at Ráith Melsigi: Bede relates that he ministered to ‘the Irish and the Picts’. In c.716 he went to Iona, where he spent the rest of his life. According to Bede, in 716 he persuaded the community to adopt the Roman dating of Easter, possibly with the encouragement of Abbot Dúnchad (qv) (d. 717). He died at the age of 90 on 24 April 729; he is commemorated in the Martyrology of Tallaght and the Martyrology of Gorman (Máel Muire Ua Gormáin (qv)) on that day.