St. Adomnán was a 7th-century Irish abbot of Iona Abbey, a renowned scholar, and biographer of St. Columba. He is remembered for his work in church law and efforts to promote peace and justice.
Saint Adomnán (also spelled Adamnan) was born around the year 624 AD in County Donegal, Ireland. He was of noble descent, and a relative of the great Irish missionary, Saint Columba. He entered monastic life and eventually became the ninth abbot of Iona Abbey, one of the most influential monastic centers in the British Isles at the time.
Adomnán is best known for authoring the "Vita Columbae" (Life of Columba), an important hagiographical work that preserves valuable historical and spiritual insights into the life of his kinsman, St. Columba. This biography is a major source of information about early Irish monasticism and the religious culture of the time.
Aside from his literary contributions, Adomnán was an important figure in religious law and diplomacy. One of his most notable achievements was the "Law of the Innocents" (Cáin Adomnáin), enacted in 697 AD. This law was one of the earliest declarations of the protection of non-combatants during warfare, especially women, children, and clerics — a remarkable concept for the time.
Adomnán was also a prominent advocate for aligning Irish Christian practices, such as the dating of Easter, with Roman customs — a divisive issue in the Celtic Church during his lifetime. He made multiple visits to the court of King Aldfrith of Northumbria, forging ties and strengthening ecclesiastical connections.
He died in 704 AD and was buried in Iona, the sacred island where he had served as abbot. He is honored particularly in Ireland and Scotland, and is often referred to as St. Eunan, especially in Donegal, where the cathedral in Letterkenny is named after him.