Who was Saint Columba? How did this Irish aristocrat become the most important figure in early Scottish Christianity? In seeking answers to these questions this book examines the different roles played by the saint in life and death, tracing his career in Ireland and Scotland before looking at the development of his cult in later times. Here we encounter not only Columba the abbot and missionary but also Columba the politician and peacemaker. We see him at the centre of a major controversy which led to his excommunication by an Irish synod. We follow him then to Scotland, to Iona, where he founded his principal monastery. It was from this small Hebridean isle that he undertook missionary work among the Picts and had dealings with powerful warrior-kings. It was from Iona, too, that his cult was vigorously promoted after his death in 597, most famously by Abbot Adomnan, whose writings provide our main source of information on Columbas career.