The Irish Abbot of Iona, an island in the Inner Hebrides. He was ninth in succession from distant relative St COLUMBA The Founder.
Life was probably a bit boring on Iona so this Abbot — being something of a scholar — filled in his time by writing a biography of The Founder.
As well as cooking up a primitive version of the Geneva Convention, his good works also included the refurbishment of Raphoe Monastery in Ireland.
Things went a bit sour when he attempted to replace Celtic Catholic customs with those of Rome, which made him so unpopular he went on an extended preaching vacation.