Geraint /ˈɡɛraɪnt/ is a character from Welsh folklore and Arthurian legend, a king of Dumnonia and a valiant warrior. He may have lived during or shortly prior to the reign of the historical Arthur, but some scholars doubt he ever existed. The name is a Welsh form of the Latin meaning old man.
Geraint's father was said to be Erbin, a herder of sheep, and according to Culhwch and Olwen, he had brothers named Ermind and Dywel. A "Geraint of the South" appears at the Battle of Catraeth (circa 600) in the 14th-century poem Y Gododdin, attributed to Aneirin. Geraint was one of the "Three Seafarers of the Isle of Britain" according to the Welsh Triads. His deeds at the Battle of Llongborth are celebrated in the poem "Geraint son of Erbin", written probably in the 10th or 11th century, and traditionally attributed to Llywarch Hen. However, Derek Bryce, following other scholars, suggests that the later, historical Geraint of Dumnonia (d. 710) may be identified as the real warrior eulogized in connection with the Battle of Llongborth in the poem, despite its title. Bryce identifies Llongborth with the 710 battle between that Geraint and Saxon leader Ine of Wessex. Hypotheses about the location of the battle range from Somerset, bordering Dumnonia, to as far north as Kingdom of Strathclyde, if the Battle of Llongborth is simply another spelling for the 710 Battle of Longecoleth . Strathclyde had rulers named Geraint and Erbin/Elfin in the same era, and was also known as Damnonia, after the Dumnonii tribe of the area in Romano-British times, and thus easily confused with Dumnonia/Devon.