314) was a Romano-British bishop, possibly from Londinium (London), Lindum (Lincoln), Camulodunum (Colchester) or Legionensium (Caerleon), who was part of the British delegation who attended the church council held at Arles, in Gaul, in AD 314.
[1] The list of those who signed the Acta – the decisions made by the Council – included three bishops from Britain, along with a presbyter and a deacon.
[7] Haddan and Stubbs note that Adelfius also appears as a signatory to a synodal letter to Pope Sylvester I; however, his see is not mentioned.
[3][11][12] Others, including Haddan and Stubbs and the 1885 Dictionary of National Biography, proposed reading the location as Legionensium (Caerleon-on-Usk), though Miller disputed this as this was also not a colonia, and seemed an unlikely place to give rise to a bishop.
[15] Adelfius is portrayed as a character in the play Aaron and Julia by Oliver Myers, set in Roman Caerleon.