Christianity and the Celts opens up for readers the impact of Christianity upon the Celtic world. Writing in a vivid style and focusing on the key figures involved, Olsen brings this distant world to life without losing historical balance and integrity. He begins by examining the Celtic world before the arrival of Christianity, and then focuses on subjects such as: the influence of Patrick; the beginnings of Irish/Celtic monasticism; Columba and the founding of Iona; Celtic missionaries; the Viking raids; and Celtic revivals through history.