When Eduard Sievers edited the Old High German translation of Tatian's Diatesseron in 1872, he believed that the manuscript which Franciscus Junius had brought to England was a modern copy of the famous ninth-century codex in St. Gall. Recent work has shown that this was an error. A reprint of Johann Philipp Palthen's first edition of the Old High German text of MS Junius 13 in the Bodleian Library is, therefore, justified on account of its importance in the history of Germanic philology. Moreover, it makes available again the text of an independent witness of a work which must have been important in missionary and pastoral work during the Carolingian period.