Manchán Magan: 'Stepping Stone between Wales and Ireland?' (2021)

Description

Lede
The Irish Sea separates Ireland from Wales, but perhaps it wasn’t always the case. There are some tantalising hints that suggest a series of giant “stepping stones” that might have made it a lot easier to cross from Wales to Wicklow long ago.

Story
Looking across the Irish Sea to Snowdonia in Wales on a bright snowclad morning is a disconcerting experience. From Wicklow, Wexford and even parts of Dublin it seems as though you could walk across to the Welsh coastline, and there are some tantalising suggestions that maybe at one time you could.

Certainly, these two coasts were closer in the past, as can be seen by the extensive remains of submerged woodland beneath Cardigan Bay, which lies directly across from Wicklow. A vast realm of twisted tree stumps and coiling roots dating to between 4000 and 5000 years ago stretch out like stunted peaks and shiny seals across the sands. Even an ancient timber walkway of coppiced branches and upright posts has been uncovered, built eons ago as the sea was inundating the land.

There's a real possibility that a land bridge linked the two regions around ten thousand years ago. It sounds like long ago, but is, in fact, recent enough that memories may still linger in old stories, such as in the medieval Welsh tales among the Mabinogion. An episode in one of the Four Branches, Branwen Daughter of Llŷr, recounts how the Welsh giant, Bendigeidfran, leads his army across from Wales to invade Ireland. The attack is described as, “an entire landscape, it seemed, moving towards Ireland.” Swineherds in Wicklow warned their leaders that, “a wood have we seen upon the sea, in a place where we never yet saw a single tree… and the wood, and the mountain, and all these things moved.” Bendigeidfran led the charge, wading through the water ahead of the fleet.

There is much exaggeration to the story, but could there be grains of truth in the story. And looking across the Irish Sea on a clear day the question that arises is whether a giant could have waded across the channel long ago, when some of the ice sheets still remained and the water levels were far lower? First off, we must acknowledge that giants are not make-believe. Genetic research has isolated a gene mutation among Irish people which causes a pituitary adenoma, a condition that can lead to gigantism in certain people. In the Hunterian Museum in London there are skeletal remains of an Irish man, Charles Byrne, who was 7ft 7ins tall. His ailment can be traced back through many generations and appears to have first arisen among the Irish 1500 years ago, but geneticists point out that it could have started as far back as 3,700 years ago. So, there were always a small proportion of very tall people in Ireland.

Furthermore, the short 80km stretch of sea between Ireland and Wales was likely shallower at times than it is today. The Mabinogion explains Bendigeidfran’s ability to cross the Irish Sea by saying, “in those days the deep water was not wide. He went by wading. There were but two rivers, the Lli and the Archan were they called, but thereafter the deep water grew wider when the deep overflowed the kingdoms.”

This description matches the claim made by some geologists that there was a temporary land bridge running between Wales and Ireland 11,000 years ago. Robin Wingfield of the British Geological Society believed that the slow northward retreat of the ice was followed at its boundary by a migrating "forebulge" as the earth's crust rebounded from the weight of the ice cap. This ridge of land would have existed for hundreds, if not thousands, of years. The distinguished naturalist and Professor of Quaternary [Ice Age] Studies in Trinity College Dublin, Frank Mitchell, was adamant that this was the case and he pictured "a very remarkable type of automatic trackway across the Irish Sea.”

Other coastal and geophysical researchers are more sceptical, believing that the sea level never dropped far enough in the channel to allow the land emerge entirely. They point to the fact that the Irish Sea floor has a great trough, 100m deep, running up the centre. Yet this deep central trough is bridged by a high ridge running east to west, roughly between Wicklow and Cardigan Bay, where Bendigeidfran had his base. It’s not quite high enough to have been exposed in the post-glacial period, but experts do speculate that there could have been a series of soggy, temporary islands that might have allowed the giant Irish "elk" make the crossing, holding up its antlers as it swam. If Bendigeidfran was indeed as tall as Charles Byrne he too might have made it across, especially if he knew where the moraine ridges of rocks left behind by the glaciers were and could leap from one to the other.

Such speculation is definitely more the realm of arts than science, but it does help to clarify in our imaginations, at least, just how strong the linguistic, trading and cultural links are between Ireland and Wales.

• https://perma.cc/NA25-WUUD (link opens in new window)