Colman was in all probability a native of the West of Ireland; born in the province of Connaught in the year 605. Not much else is known about his early adult life, except that he entered the monastery at Iona and became a monk during the abbacy of Segenius, was a devoted disciple of St. Columba, and spent years in study and fellowship with his contemporaries St. Finian and St. Aidan.
After the death of St. Finian in 661, Colman succeeded him as the third Abbot-Bishop of Lindisfarne. Lindisfarne was the most important monastery in Northumbria, England, close to the royal castle at Bamburg. The Venerable Bede gives a glowing account of the church of Lindisfarne under Saint Colman’s rule. He emphasized the example of frugality and simplicity of living set by Bishop Colman and the complete devotion of his clergy to their proper business of imparting the word of God and ministering to their people.