Tewdwr Mawr

Tewdwr Mawr (Breton for "Theodore the Great";Cornish: Teudar Maur or Teudaric; Welsh: Twedr; Latin: Theodorus; French: Thierry; mid-6th century) was an early medieval king in Armorica (now Cornouaille, France) and Cornwall.

Tewdwr was a member of the royal family of Cornouaille in Armorica. His father was Hoel, who figured in Welsh mythology about the Matter of Britain and Tristan and Iseult. While Tewdwr was still young, his grandfather Budic II was overthrown and forced into exile at the court of Aergol Lawhir of Dyfed. Budic successfully restored himself in the 540s but Hoel seems to have predeceased him. The king attempted to protect his succession by negotiating with a neighbouring ruler, Macliau of the Veneti, so that whichever lived longer would protect the young heir of the other. Upon Budic's death, however, Macliau invaded and annexed Cornouaille (r. c. 544–577).

Tewdwr fled to Cornwall and ruled over Penwith from Carnsew near the mouth of the Hayle River. He became infamous for his hostile reaction to Irish missionaries. He opposed Breage's mission (although Sabine Baring-Gould placed its arrival around 500), first compelling them to land at Reyvier instead of Carnsew and then later martyring several of its members, including Ia of Cornwall; Saint Gwinear met with a similar fate, being thrown with his followers into a pit of reptiles.

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