 His original writings, preserved only in fragments, show him to have been a devoted student and a man of wide and varied learning.His best-known work is the "Codex Fuldensis", one of the most ancient manuscripts of the Vulgate, prepared under his direction, and which he himself revised and corrected.In this codex the place of the Four Gospels is taken by a harmony of the Gospels, or as he himself terms it in the preface, a single Gospel composed from the four.