Meurig, King of Gwent & Glywysing
Meurig was the son of St. Tewdrig. He took on the Gwentish throne upon his father's abdication in the early-7th century. He was a Warrior King who kept the Saxons at bay and reunited his Kingdom with Ergyng by marrying Princess Onbrawst daughter of King Gwrgan Fawr (the Great) of that Kingdom. Her brothers were apparently no match for Meurig's expansionistic policies. He was a great patron of Llandaff Cathedral where he was eventually buried. His eldest son having, apparently, predeceased him, Meurig was succeeded by his grandsons, Ithel and Morgan Mwynfawr, Joint-Kings of Ergyng.
Some researchers claim he used the title "Uther Pendragon" which translates as Wonderful Commander. He is thus identified as the High-King Arthur's father.