Dubricius - Also known as St. Dubritius, Dyfig, or Devereux. Essay says that he was a monastic founder and died about 545. - http://www.saintpatrickdc.org/ss/1114.htm#deve
St. Dyfrig, Bishop of Ergyng - Biographical details of this tutor of many saints. - http://www.earlybritishkingdoms.com/bios/dyfrig.html
St. Dubric - Welsh bishop and confessor, d. 612. Also called St. Dubricius or Dyfrig. - http://www.newadvent.org/cathen/05179a.htm