Postprint erschienen: Bamberg, Otto-Friedrich-Universität, 2021

96 genuine letters of Pope Pelagius I are transmitted mainly as fragments in canonical collections. Apart from an early collection compiled at Arles, the most important transmission is that in the famous Britannica and other legal collections of the late eleventh century. Compared to other papal correspondences, the transmission is well known and relatively easy to understand. No new letters have been reported for more than a century, and since 1956 there is a reliable critical edition. Pelagius‘ letters are therefore used to evaluate critically the first volume of the new edition of the Regesta pontificum. A comparison between the second edition of the Regesta pontificum, the critical edition of the letters, and the third edition shows that the latter does not use the critical edition in many cases, and at various points it fails to meet even the standards of the second 1883 edition. There is hope at least that the numerous smaller errors will be mended in the forthcoming online version.