Gildas was a 6th century British monk and historian, best known for writing a work entitled De Excidio et Conquestue Britanniae.  He is attributed with the establishment of many churches and monasteries and toward the end of his life went on to found the monastery of Saint-Gildas-de-Rhuys in Brittany, France.

A 12th century 'life' of St Gildas (written by Caradoc of Llancarfan, a contemporary of Geoffrey of Monmouth) links him to the legend of King Arthur and those events from it that are set within Somerset.