Dyfan of Merthyr
Dyfan (2nd cent.) is said to have been one of the missionaries sent to the Britons by Saint Eleutherius at the prayer of the king, St. Lucius. His name has been Latinised into Deruvianus or Damian; or rather it is some such Latin appellation which has been rendered into the Celtic Dyfan. His church of Merthyr Dyfan shows the popular tradition that he ended his days by martyrdom.