Teulyddog

Saint Teulyddog (in Old Welsh Teulydawc, in Medieval Latin Toulidauc or Thelaucus) was a Welsh saint of the 6th century, counted a disciple of Saint Dubricius. He is said to have fled with many others to Brittany during the Yellow Plague of the 540s.

Returning to Wales, he joined Saint Teilo and is credited with founding the ecclesiastical settlement (clas) in Carmarthen, within the walls of the old Roman town of Maridunum; it took its medieval name, Llan Teulyddog, from him. Later the land of the clas was given to the priory of Saint John the Evangelist and Teulyddog, where the Black Book of Carmarthen was probably written. After the Norman conquest, the patronage of the town passed to Saint John the Evangelist, but the Benedictine abbey (later an Augustinian priory) remained under the joint dedication of Teulyddog and Saint John. He is honored as a saint of the undivided Church, in the old Welsh calendars.