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Ancient Stories Recalling the Submergence of Wales

In the aftermath of the last great ice age, more than ten thousand years ago, when the first people reached what today we call Wales, it was almost certainly much closer to Ireland.  There were probably even ways to walk between the two.  Yet as the ocean surface rose (because the land ice was melting), so the Irish Sea became wider, encroaching on inhabited lands on both sides.  Owing to the fact that Welsh traditional stories tend to have been well conserved (relative to some other cultures), we have today a richness and diversity of stories recalling this ocean-surface rise and its effects.

Map of Wales (Author’s own)

This is not a comprehensive account but I will start with Swansea Bay about which there are stories from different sources that recall when it was all dry land, when the shoreline was further out to sea by several kilometres compared to today.  For example, in an AD 1697 account, Edward Llwyd stated that the coast once ran straight from Oystermouth in the west to Aberavon in the east, “divided from it only by a small rivulet till [one day] ye sea Broke in and made a considerable distance between both parishes”.

And when one of the greatest Victorian authorities on Welsh folklore, John Rhys, visited Swansea in the 1870s, he chatted with the oyster dredgers living there.  They told him stories about how the coast had formerly been three to five miles further out.  Rhys also spoke with elderly residents who told him the old story that the coast had once stretched from The Mumbles straight across to Kenfig Burrow … and that it had been covered by a forest named Coed Arian, the Silver Wood.  And should you ever doubt that four thousand years and more ago, people were walking the paths of the Silver Wood, why, their footprints are still there!

(A) Basal contact of Peat A showing the blue-grey clays and the thin peat layer on which the prints are visible. (B) Possible human footprint within the surface of Peat A. (C) Short footprint trail within a water filled beach runnel. (D) Possible human footprint within the surface of Peat A. (E–G) Optical laser scans of possible human footprints on the foreshore at Kenfig. The scans are colour rendered with 5 mm isopleths, cooler colours indicate greater depth.
All from Bennett and others (2010), Proceedings of the Geologists Association.

Moving north, we come to Cardigan Bay, the massive sweep of which dominates the coastline of Wales.  The offshore area here is comparatively shallow, a few tens of metres for a few tens of kilometres, which helps explain why there are so many stories about inhabited lands in Cardigan Bay becoming submerged.  The best-known is that of Cantre’r Gwaelod, the “city” or “cities” in Cardigan Bay, then a vast fertile region now apparently all below sea. The most common narrative detail is that the city of Cantre’r Gwaelod was the seat of King Gwyddno, who ruled the surrounding countryside (Maes Gwyddno). Yet, the city was one that had been threatened by the ocean for a long time and had, as a consequence, a series of tidal (sluice) gates that were closed at high tide to prevent the city from being flooded. One night, the king’s steward Seithennin became intoxicated and failed to close the flood gates, so the city was inundated and abandoned.

There are numerous detailed stories about Cantre’r Gwaelod that specify its extent, approximate location and links to various culture heroes. Yet, no tangible evidence of its existence has ever been uncovered, leading some to insist that it is an enduring fictional cultural narrative. Others disagree, highlighting the probable origin of such stories in people’s observations of changes in coastline position, stories sustained and periodically rejuvenated by both continued coastal submergence and the actions of new sets of culture heroes. Stories about Cantre’r Gwaelod feature prominently in my recent books, The Edge of Memory (2018) and Worlds in Shadow (2021).

There are several stories about Cantre’r Gwaelod and other submerged lands from Aberdyfi (Aberdovey) on the coast of Cardigan Bay including one that says you can hear the undersea bells ringing from its church steeples if you stand on the foreshore at low tide on a still night.

Further north, one of the submerged lands in Caernarvon Bay is centred around Caer (Castle) Aranrhod, marked today, it is said, by a reef of stones but mostly beneath six metres or so of ocean. A range of traditions has been recorded, especially in the comprehensive collection of Welsh stories from the 12th and 13th centuries known as the Mabinogian. Several mention how Caer Aranrhod was once contiguous with the mainland and how its human‐made features can be seen below the ocean surface today.

Finally, even further northwards, lies the submerged land known as Tyno Helig (Helig’s Vale) off the Conway coast. Some accounts explain the story by records of a ‘great inundation’ here about AD 634 when the area was ruled by (Lord) Helig ap Glannawg, who had angered the ‘sea folk’ and was punished as a consequence. Through the sea‐floor Lavan (‘weeping’) Sands that cover the area now, the ruins of houses and a causeway were apparently once visible although these were probably glacial outwash structures easily mistaken for artificial constructions.

Old view of Caernarvon (Caernarfon) Bay

Recent research suggests stories about Caer Aranrhod and Tyno Helig recall land submergence more than 7500 years ago while stories about Cantre’r Gwaelod are likely to be slightly older, a minimum of 7800 years old.  It is a credit to Welsh oral communicators that for more than seven millennia, so many stories have been nurtured and effectively passed on here. 

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