Harlech and ‘The Mabinogion’
Much of the Mabinogion saga is based in the Ardudwy region of North Wales. It was from the ‘Castle Rock’ or ‘Rock of Harlech’ (where Harlech Castle now stands) that the Welsh King Bendigeidfran first saw the Irish longboats of Matholwch loom into view with their shields turned upside down as a sign of peace. This peace was soon broken by Efnisien due to his jealousy over his half-sister being espoused to Matholwch. The story can be found in Branwen the Daughter of Llyr.
There is no evidence that the ‘Castle Rock’ was inhabited before the castle was built there between the years 1282 and 1289 by King Edward I. The Irish Sea was also much closer to the castle at this time, since the castle could be supplied via the sea when it was built. Today the sea is about half a mile away from Harlech Castle.