One of my favorite types of myth concerns lost kingdoms drowned under the waves. Not only are these stories cool, they raise in a stark way one of the best questions about myth: to what extent is it a kind of history?
Humans lived through one of the great land-drownings in earth's history, the 100 meter (330 feet) sea-level rise at the end of the last Ice Age. This was not, in the grand scheme of things, so long ago; in my part of the world the Chesapeake Bay was just a river valley until around 8,200 BC. Doggerland, a lost chain of islands in the North Sea, may have drowned around the same time. The Black Sea does not seem to have been joined to the Mediterranean until about 5600 BC, and some people think that event was accompanied by catastrophic flooding. Most glacial melting was complete by 5000 BC, but in some areas there has been more localized sea level rise even more recently. It seems plausible to me that these events were remembered.
Which brings me to the west coast of Wales, and Cardigan Bay in particular. The Celts had multiple stories about drowned cities, provinces, and kingdoms. The most famous concern Ker Ys in Brittany, but Cardigan Bay has its own cluster of legends.
Consider this excerpt of a medieval map of Britain. Called the Gough Map, it was made sometime between 1300 and 1350. It is quite good as medieval maps go; all of the hundreds of towns and rivers it names actually existed. So why does it show two substantial islands in Cardigan Bay?
Wikipedia has a good summary of the main local legend, under the heading Cantre'r Gawelod:
Cantre'r Gwaelod, also known as Cantref Gwaelod or Cantref y Gwaelod (Welsh for 'The Lowland Hundred'), is a legendary ancient sunken kingdom said to have occupied a tract of fertile land lying between Ramsey Island and Bardsey Island in what is now Cardigan Bay to the west of Wales. It has been described as a "Welsh Atlantis" and has featured in folklore, literature, and song.
There are several versions of the myth. The earliest known form of the legend is usually said to appear in the Black Book of Carmarthen, in which the land is referred to as Maes Gwyddno (Welsh for 'the Plain of Gwyddno'). In this version, the land was lost to floods when a well-maiden named Mererid neglected her duties and allowed the well to overflow.
The popular version known today is thought to have been formed from the 17th century onwards. Cantre'r Gwaelod is described as a low-lying land fortified against the sea by a dyke, Sarn Badrig ("Saint Patrick's causeway"), with a series of sluice gates that were opened at low tide to drain the land.
Cantre'r Gwaelod's capital was Caer Wyddno, seat of the ruler Gwyddno Garanhir. Two princes of the realm held charge over the dyke. One of these princes, called Seithenyn, is described in one version as a notorious drunkard and carouser, and it was through his negligence that the sea swept through the open floodgates, ruining the land.
In the sea, about seven miles west of Aberystwyth in Cardiganshire, is a collection of loose stones, termed Caer Wyddno, "the fort or palace of Gwyddno;" and adjoining it are vestiges of one of the more southern causeways or embankments of Catrev Gwaelod. The depth of water over the whole extent of the bay of Cardigan is not great; and on the recess of the tide, stones bearing Latin inscriptions, and Roman coins of various emperors, have been found below high-water mark: in different places in the water, also, are observed prostrate trees.And there are these linear rock features, known as Sarnau, which run hundreds of meters out into the sea. Modern geologists say they are just unusual glacial deposits, but you can see why medieval people thought they might be ancient causeways leading to now vanished islands.
But what has gotten a lot of attention in recent years is the sunken trees. Starting around 2010, a series of storms, culminating in the hurricane of 2019, have exposed the remains of what people call "the submerged forest at Ynyslas." This was a temperate forest, with oak, pine, birch, willow and hazel trees. Radiocarbon dating places its drowning around 4000 to 5000 years ago.
So far as I can tell, there is no agreement about whether there might have been solid land in Cardigan Bay in 1300. But there are scholarly articles arguing that there was. If so, it would have been quite low-lying, and notice that the Gough Map does not show any village on the islands. So if there was land, it was presumably marshy and used mainly for grazing cattle.
So many stories in the world, so much history, so much to occupy my mind.