OUDOCEUS (fl. 630?), bishop of Llandaff, is generally regarded as having succeeded Teilo in that see. There is a life of him in the 'Liber Landavensis' (ed. Evans, pp. 130–9), abridged by Capgrave (Nova Legenda Angliæ, p. 258) and by the compilers of 'Acta Sanctorum' (2 July, i. 318). According to this, he was the son of Budic, son of Cybrdan of Cornugallia (Cornouaille in Brittany), and Anauued, daughter of Ensic of Dyfed (West Wales). Budic is known to have been king of the Bretons about 500 (L'Art de verifier les Dates, vol. xiii.), and Ensic was Teilo's father. Oudoceus was trained, it is further said, by Teilo, and on his death was elected his successor, receiving consecration at Canterbury. As bishop he was contemporary with Cadwgan of Dyfed (fl. about 670) and Meurig of Glamorgan (fl. about 600). It was during his time the English seized the region between the Wye, the Dore, and the Worm (Herefordshire). At the close of his life he resigned his bishopric, and withdrew to the solitude of Lann Enniaun, or Lann Oudocui (Llandogo, Monmouthshire), where he died on 2 July.
The chronological inconsistencies of this life deprive it of nearly all value. It appears to have been written in part in Brittany, but the reference to Canterbury shows that it re- ceived its present form from a British hand, probably not long before 1150. Doubtless Oudoceus was a Breton, for in several of the Welsh catalogues of saints he is said to have come over with Cadfan (Iolo MSS. ff. 103, 112, 134; Myvyrian Archaioloyy, 2nd edit. p. 423), but the parentage of the life can hardly be accepted. In the 'Liber Landavensis' (pp. 140-60) is recorded a number of grants of land said to have been made to Oudoceus during his episcopate by various princes of South-east Wales. These documents, although they may not perhaps be authoritative as to the claims they were put forward to support, nevertheless appear to embody historical facts, and from them it would seem that Oudoceus was the contemporary of Meurig ap Tewdrig, king of Glamorgan, and his grandson Morgan Mwynfawr [q. v.], who flourished in the early part and the middle of the seventh century. This date, which is favoured by Haddan and Stubbs (Councils and Ecclesiastical Documents, i. 160), is consistent with the statement in the life that it was during the episcopate of Oudoceus that the 'English conquered the region south-west of Hereford, for the advance in this direction is generally supposed to have been made under Penda.
Oudoceus is the latinised form of old Welsh Oudocui, which in modern Welsh would be Euddogwy. In the catalogues of saints the name appears as Docheu, Dochwy, and Dochdwy (Myvyrian Archaiology, 2nd edit. p. 423; Iolo MSS. 103, 112, 134). The church of Llandogo, near Tintern, is dedicated to Oudoceus.
[Liber Landavensis, ed. Gwenogfryn Evans; Rees's Welsh Saints.]