Áedán mac Gabráin
The Irish borrowed the name by the late 6th century (either from an early Archaic Welsh or Cumbric form "Artur"), producing Old Irish "Artúr" (Latinized as "Arturius" by Adomnán in his Life of St. Columba, written circa 697–700), The earliest historically attested bearer of the name is a son or grandson of Áedán mac Gabráin (died 609).