Columba, called by his countrymen Columb-Kille or Cille ("dove of the cell"), a saint of the Roman Catholic church, styled also the apostle of Caledonia, born at Gartan, Donegal, Ireland, in 521, died in Iona, June 9, 597. His father was of the royal race of Niall or O'Donnell, his mother a princess of the reigning family of Leinster. Educated from boyhood by the priest who had baptized him, he passed into the great monastic school of Clo-nard, under Finnian, styled magister sanctorum, who ordained him deacon, and finished his course in the monastery of Maghbile, Down, under another Finnian or Finbar, afterward bishop of Lucca in Italy. His own wealth and powerful connections enabled him to found in Ireland 37 monasteries before his 25th year. He resided at Derry, superintending the other establishments, and fostering in all the love of rural labor, the culture of sacred and profane letters, and the work of translating the Old and New Testaments. A copy which he had furtively made of a rare manuscript of the psalter involved him in a suit with his old master Finnian, which was carried before the king at Tara, who decided against Columba; and soon after, a young prince of Connaught who had fled to his monastery for asylum having been taken thence by the king's officers and executed, Columba vowed revenge.

He hastened into his native province of Tyrconnell, roused all his kinsfolk to arms, and led them against the king, who was defeated at Cool-Drewny. Excommunicated in a synod for this bloodshed, Columba wandered from monastery to monastery, until his confessor as an expiation of his guilt commanded him to leave Ireland for ever. With 12 companion monks he landed on Iona (then called I or Hy, afterward named from him I-Columb-Kill or Icolmkill), where they built cells and devoted themselves to the bodily and spiritual wants of the inhabitants of this and the neighboring isles and the mainland. Iona being in the territory of an Irish colony of Dalriadians, their prince Oonnal, a kinsman of Columba, bestowed the island on him in 563. His biographer and contemporary Adamnan describes the moral transformation which took place in him. Subdued by remorse for the blood he had caused to be shed, he sought out guilt and suffering that he might purge away the one and alleviate the other. His reputation grew with his community, and the churches and monasteries which they founded on every side.

The Dalriadian colony was renovated in 574. Aidan, Connal's successor, sought Columba on his island to confess his sins, and was there blessed and crowned king by the abbot, the first instance of such a ceremony in the history of the West, and the stone which served Aidan for a seat is now in Westminster abbey. From the territory of the Irish-Scots, Columba and his monks had pushed their missionary excursions into the adjoining districts inhabited by the heathen Picts. The opposition of their king was overcome by a miracle; while miracles of patience and devotion overcame the long resistance of the druids, until all Scotland was Christian, and the monastery of Deir (or "Tears" ) arose on the remotest shore of Buchan, where it flourished 1,000 years. Ancient traditions attribute to Columba the foundation of 300 monasteries or churches. Modern learning has discovered and registered the existence of 90 churches whose origin goes back to him. King Aidan was still held tributary to Ireland; and at his urgent solicitation and that of the Irish communities which had never ceased to regard Columba as their superior, he consented to visit Ireland. A parliament was held in Drum-keath, the king of Ireland and Aidan presiding; princes, nobles, bishops, and abbots discussed for a whole year the interests of church and state.

The tribute was remitted to the Dalriadian prince, and his thorough independence acknowledged; the institution of the bards was saved from outlawry, old feuds were healed, a solid basis for future concord was established, and salutary laws were enacted. Columba maintained exact discipline in all his houses. The time not given to missionary labors, prayer, and chanting the divine office, was devoted to manual and intellectual labor. Agriculture was a prime necessity for the monks, and they taught it to the people. Out of doors they labored in the fields, built or repaired churches and monasteries, and constructed wicker boats covered with hides, in which the missionaries ventured to the Faroe isles and to Iceland. Indoors they transcribed the classics, and copied and illuminated the Bible. In all these duties Columba was foremost to the very last; his cell in Iona remaining until his 76th year what it had been at first, made of willow rods and hay, with the bare ground for a bed and a stone for pillow. He died sud-' denly, having before predicted the hour, while celebrating the midnight office.

His life and the fragments of his poems are in Montalem-bert's "Monks of the West".