Wikipedia
Restitutus was a Romano-British bishop, probably from London, one of the British delegation who attended the church synod or Council held at Arles ( Arelate), in Gaul, in AD 314.
The list of those who signed the Acta, the decisions made by the Council, included three bishops, along with a " presbyter" and a " deacon", from Britain. The British bishops were Eborius "de civitate Eboricensi" – from the city of Eboracum ( York); Restitutus "de civitate Londenensi" – from the city of Londinium ( London); and Adelfius "de civitate Colonia Londenensium" – that is, from the " colonia of the people of London". The text, which survives only in a number of later manuscript copies, is clearly corrupt in assigning two bishops to London. Since London was not a colonia, suspicion has fallen on the place of origin of Adelfius, bishop of the "colonia of the people of London".
Most authorities have suggested emending "Colonia Londenensium" to "Colonia Lindensium" – the colonia of the people of Lindum ( Lincoln).
However S. N. Miller considered that the word "colonia" was also suspect; he pointed out that although many other coloniae had sent bishops to Arles, among them Cologne, Trier and Lyons, none had been designated "colonia" in the list. Miller argued that "de civitate Colonia Londenensium" was a mistake for "de civitate Camu/lodunensium" – "the city of the people of Camulodunum" ( Colchester). This view was supported by archaeologist Sir Ian Richmond. Others have identified Adelfius as Bishop of Caerleon-on-Usk.
Notwithstanding the debate about the role of Adelfius, it seems most probable that the identification of Restitutus as Bishop of London was correct. However, no more is known about him, nor about his predecessors and successors in the Romano-British see of London. His name does not appear in the list of supposed early " Archbishops of London" that the 16th-century historian John Stow attributed to Jocelin of Furness. Stow himself noted this anomaly, and the fact that Restitutus was listed as a bishop and not an archbishop; this, he felt, cast doubt on the authenticity of the list of archbishops. Later writers attempted to reconcile the two sources, usually by inserting Restitutus into "Jocelin's" list, either between Hilarius and Guitelinus, or after Guitelinus.