The text edited here as the Vita Sancti Clitauci consists of the passion of the saint, a posthumous miracle, an account of two hermits who dwelt near Clydog’s shrine, the gift of Merthyr Clydog to Llandaff, another posthumous miracle involving a gift, and a further short record of a gift to Clydog and Llandaff (cf. Davies 2003: 122). All this text is preserved in two almost identical copies, one in the Liber Landavensis and the other in Vespasian A. xiv. Of the two, the copy in the Liber Landavensis is superior to the other in almost every respect and has been used as the base text for this edition. However, comparison with the longer Lives of SS. Dyfrig and Teilo, which also appear in both the Liber Landavensis and Vespasian A. xiv, suggests that the version of the Life of St Clydog in Vespasian A. xiv was not copied from that in the Liber Landavensis, but rather that both of them were copied from a common exemplar. If this were indeed the case, then it is interesting that both copies contain the same gloss in §4 (.i. Nant Cum, ‘that is Nant Cwm’), implying that the gloss was also present in the common exemplar. The chief difference between the two copies of the Life of St Clydog concerns their relative ordering of the sections: in the Liber Landavensis, the six sections appear in the order in which they have been edited, whereas in Vespasian A. xiv §5 and §6 appear between §1 and §2. It has been suggested that the latter arrangement is the more natural, because the post-mortem miracles appear as a group and the formal charter recording the gift of the land of Merthyr Clydog (§4) appears at the end (Hughes 1980: 61; Davies 2003: 124). Be that as it may, the arrangement of Vespasian A. xiv is less consistent with regard to the chronology of events than that of the Liber Landavensis, for §5 and §6, unlike sections 1–3, record gifts to Clydog and the church of Llandaff together, presupposing the giving of Merthyr Clydog to Llandaff, as occurs in §4. Perhaps, rather, Vespasian A. xiv reveals something of the process by which the Life was compiled; certain sections may have originated as rewritten versions of texts taken from one or more separate sources, which may have been assembled together differently in each of the surviving copies of the Life (cf. Davies 2003: 124).

The text in the Liber Landavensis was copied into quire 11 by scribe A of that manuscript ((MWM 129, 135, 154). Quire 11 is part of the continuous sequence formed by quires 7 to 14, which were all copied by scribe A uninterrupted. They contain the Lives of SS. Dyfrig, Teilo, Euddogwy and Clydog, and the main sequence of charters from Dyfrig to Herewald. The text in Vespasian A. xiv was copied into quire 12 by scribe H of that manuscript, and was corrected by a contemporary scribe with reference to the exemplar.

List of manuscripts
Liber Landavensis, 85ra–86va (c.1132–4)
Vespasian A. xiv, 84v–86r (s. xii^3/3)