Gwyddno Garanhir, King of Meirionydd
King Gwyddno Long-Shanks (or occasionally Gwyddno Cornaur - Golden-Crown) lived in the early to mid-6th century. The son of King Gwrin Farfdrwch of Meirionydd, he is best known for the loss of a major part of his kingdom to the Atlantic Ocean. Western Merionydd, known as Maes Gwyddno, was part of the Cantref Gwaelod, a legendary area of low lying land that was kept safe from the constant threat of flood by a large stone dyke known as Sarn Badrig (one of a number of natural pebble ridges to be seen north of Barmouth at low-tide). It was during Gwyddno's reign that the sluice gates of the dyke were supposedly left open by a maiden named Mererid, probably through the drunkenness of Seithen Hen (the Old), King of Caer Rihog, an adjoining region of the Cantref. The waters inundated the land, covering some sixteen fine cities including the King's Palace at Caer Wyddno. Gwyddno was thus forced to move his court to higher ground in the East. The major port of his reduced Kingdom became Porth Wydno (Borth) and the King had a fishing weir between Aber Dyfi and Aberystwyth called Gored Wyddno. He married a lady called Ystradwen and had sons named Idris, Rhun, Dyfnwal, Eifionydd, Elffin, Sandde and Edern. Gwyddno Garanhir (Long-Shanks) should not be confused with his contemporary, Gwyddno ap Cawrdaf of Northern Britain.