<b>Although related to one of the ruling families of Ireland, Columba (c 521-97) became a central figure in the ''Age of Saints'' by setting out from his native land and founding his famous monastery on the island of Iona.<br><br></b>It was from here that priests and monks played a key role in converting the Picts of Scotland, here that countless penitents came on pilgrimages and that the King of Dalriada (Argyll) came to be consecrated. Adomnán''s <i>Life</i>, writes Richard Sharpe, is the fullest early account, offering a ''vivid depiction of the abbot among his own monks, written on the spot by the saint''s successor one hundred years after Columba''s death''.<br><br>Drawing on extensive written and oral traditions, Adomnán presents Columba as a man distinguished for his prophetic and miraculous powers, whose life was filled with angelic apparitions and whose dying days were spent preparing for his departure. A stimulating Introduction sketches in the background,