The title is taken from the hymn Be Thou My Vision, a famous reworking of the most familiar of all the ancient Celtic 'Breastplate Prayers', the Breastplate of St Patrick. This book draws upon the seventh century Breastplate of Saint Fursa. History doesn't go into great detail in its record of Fursa's life and Be thou my breastplate doesn't pretend otherwise. The text takes what is known of his story and reflects on his prayer in daily bite-size pieces. Each brief chapter unpacks and applies the prayer's contents for the reader, drawing out the fresh insights and profound challenges that come from encountering a Christian brother from another world. Though written in a disarming format and with gentle tone, the text is not without grit and guts, nor without an edge, coming as it does from a seemingly familiar yet quite foreign form of the Christian faith: the Celtic way of giving oneself to God, and invoking God's blessing and protection on the one offering the prayer.