Columbanus (d.615), the Irish monk and founder of such important centres as Luxeuil and Bobbio, was one of the most influential figures in early medieval Europe. His fiery personality led him into conflict with Gallic bishops and Roman popes, and he defended his position on such matters as monastic discipline in a substantial corpus of Latin writings marked by burning conviction and rhetorical skill. However, the polish of his style has raised questions about the nature of his early training in Ireland and even about the authenticity of the writings which have come down to us under his name....