St Columba is one of the most important figures in the early history of the British Isles. A native of Donegal and a nobleman of royal ancestry, his outstanding religious career spanned both sides of the Irish Sea. On the Scottish island of Iona he founded his principal monastery where he served as abbot until his death in AD 597. Iona eventually became the centre of a powerful federation of monasteries that preserved a memory of Columba and nurtured...