Overlooking Aberdovey’s sea front is a little white shelter on a small hillock, a popular destination with tourists and dog walkers known in the 19th Century as Pen-y-Bryn, which translates as Head of the Hill.  The original name of the hill may have been Bryn Celwydd, Hill of Lies, which is recorded on a chart of the Dyfi Estuary dating to 1748.   A number of guides to Aberdovey place Aberdyfi Castle on that spot.  For example, in Aberdyfi: The past Recalled by Hugh M. Lewis has a page describing the castle, “possibly a motte and bailey castle or more probably a castle of wattle and daub which was defended by a stockade,” locating it at Pen-y-Bryn.  However, although it is recorded that certain historical events clearly took place at a castle of this name, and it receives particular mention in the late 12th-early 13th Century Brut-y-Tywysogion (Chronicle of the Princes) compiled at Strata Florida abbey, the identification of the castle with the bandstand hill, and even with Aberdovey itself, is very doubtful.

To begin with, Pen-y-Bryn always seemed to me a most improbable as the site of a castle, even a small one, even allowing for substantial alteration of the profile of the hill over time.  In a motte and bailey arrangement a fortification sits on a natural or artificial mound with an accompanying settlement in a walled/fenced area at its foot, sometimes surrounded by a moat or ditch.  Pictures of ruins and artistic reconstructions based on excavations indicate that the motte might support a fortification that was little more than an elaborate shed, as this reconstruction from the Dorling Kindersley Find Out website suggests.  That nothing substantial could have been built on the Pen-y-Bryn site does not rule it out of being Aberdyfi castle, but the events that are described below would indicate that a large structure would have been required to defend an important fortified settlement, particularly one selected for the vital political assembly that established the primacy of a Welsh prince as ruler of most of Wales.

The Aberdyfi Castle was twice used as a base for important documented meetings of Welsh rulers, first in the 12th and then in the 13th Century, but the name is also connected with a much less secure event that allegedly took place in the 6th Century.  A rather more plausible alternative to Pen-y-Bryn for the castle is the site of Dolmen Las on the south bank of the Dyfi at Glyndyfi in Ceredigion, suggested by a number of authors.

What is clear is that wherever the castle was located, it was a Welsh one, rather than an English one captured by the Welsh.  The Norman invaders were innovators of the use of castles in Wales, but it was not long before Welsh leaders, observing and suffering the effects of this new powerful strategic device, were able to learn from it and build their own versions.  Rhys ap Gruffudd the powerful 12th century ruler of Deheubarth was amongst the first to take to castle building, and in his biography of Rhys, Turvey suggests that this castle was one of his.

Aberdyfi is first connected with Maelgwyn Fawr (Maelgwyn the Great, Maglocunus in Latin), descendant of Cunedda, and ruler of Gwynedd.  This is mentioned by Davies who says that “according to tradition it was at Aberdyfi that the suzerainty of Maelgwyn Fawr had been recognized seven hundred years earlier.”   This apparently endowed Aberdfyi with a certain status as a place associated with the triumph of a Welsh ruler in achieving a status approaching that of a king.

According to Turvey, Aberdyfi Castle itself seems to have been founded by Rhys ap Gruffydd (1132-1197) in 1156, the ruler of Deheubarth, the second most important region in Wales, in order to counter the expansionist policies of  Owain Gwynedd (or Owain ap Gruffudd, 1100-1170), ruler of the most important region at the time, Gwynedd.  Rhys and his brothers had invaded Ceredigion in  1153, having already consolidated their position in Dyfed and Ystrad Tywi, and by the time Henry II came to power, John Davies says that Owain Gwynedd’s realm “extended almost to the walls of Chester,” taking in much of the earldom of Chester and the kingdom of Powys.  The northern frontier of Deheubarth and the southern border of Gwynedd met at the river Dovey, making the river strategically significant.  Rhys was continually at war with the Norman Marcher lords to the east, and in 1158 Roger de Clare captured the castle in but was ousted by Rhys in the same year. 

In 1216 an important meeting took place at Aberdyfi Castle, 15 years after the death of Rhys.  Its purpose was to formalize the position of Llywelyn ab Iorwerth (c.1173-1240), grandson of Owain Gwynedd who became known as Lywelyn Fawr (Llwelyn the Great), to receive the homage of other Welsh rulers and to divide Deheubarth among the descendants of Rhys ap Gruffudd.  Llywelyn ab Iorwerth was born in Gwynedd, which throughout the early Middle Ages had shown the most promise for becoming the leading territory in Wales and a unifying force for the various regions that made up Wales.  The assembly was intended to reinforce the position of Llywelyn as pre-eminent ruler in Wales.   At the Aberdyfi castle gathering minor rulers of the Deheubarth territory confirmed their homage to Llywelyn, and in return Llywelyn divided Deheubarth amongst the descendants of its deceased ruler Rhys ap Gruffudd.   Aberdyfi Castle was probably chosen for the meeting partly because of the Maelgwyn Fawr connection, lending historical gravitas and integrity to the event.

So where was Aberdyfi Castle?  Even though it has been claimed that there may have been a Welsh fortification on the bandstand site, it is clearly not a suitable venue for the types of assembly described above.  Instead, a far more probable venue is Domen Las, which appears to be the remains of a motte at Ysgubor y Coed near Glandyfi (translating as bank of the river Dyfi) on the south side of the river Dyfi in Ceredigion, map reference SN68729687.  This fits in with the identification of Rhys as its builder and its location in his Ceredigion territory in Deheubarth.  The name Aberdyfi simply means “mouth of the Dyfi” and although Glandyfi is not at the mouth of the estuary, it is located at the point at which the river begins to open out into the estuary and may have been a crossing place. More significantly, Domen Las faced the mound of Tomen Las near Pennal in Gwynedd (SH697002), which may have been a motte established by one of the Gwynedd rulers, and possibly in use at the time that Aberdyfi Castle was built.  In addition, from Owain Gwynedd’s point of view, there would have been an obvious strategic link between Gwynedd and Deheubarth.  Dividing up Deheubarth from a point within Deheubarth but just over the border from Gwynedd and in sight of it would have been a powerful message to the descendants of Rhys.  Finally, although the 6th Century Maelgwn association with Aberdyfi pre-dates Rhys’s castle by five centuries, it may have had something to do with the castle’s name.

Domen, meaning mound, and las meaning green in old Welsh (blue in modern Welsh) describes the site perfectly.  It is an overgrown mound on the edge of the river Dyfi.  John Wiles describes it as follows on the excellent Coflein (The online catalogue of archaeology, buildings, industrial and maritime heritage in Wales) website:

The medieval castle of Domen Las is represented by a castle mound or motte. This is notable for the way that it is fitted into the natural topography and for the remarkable configuration of its ditch.

The castle faces north-east across the upper Dyfi estuary towards Pennal, the court of the Princes of Gwynedd in Merioneth (see NPRN 302965), and was built in 1156 to counter those Princes’ ambitions in Ceredigion. It may then have been the sole castle in Geneu’r-glyn commote, as Castell Gwallter at Llandre is not heard of after 1153 (see NPRN 92234). Domen Las is probably the castle of Abereinion mentioned in 1169 and 1206.

The castle mound is set near the northern tip of an isolated straggling rocky ridge rising from the marshes. It is a circular flat-topped mound roughly 34m in diameter and 5.0m high. It is ditched around except on the south-east, where the ground falls steeply into the marsh. On the west side a rocky ridge serves is co-opted as a counterscarp. On the north side the ditch has the appearance of a regular basin, closed on the east side by a wall of rock pierced by a narrow gap. This could be a pond or cistern, and is surely an original feature.

There are no traces of any further earthworks. The castle mound was probably crowned by a great timber-framed tower and it is likely that a princely hall and associated offices stood nearby. These could have occupied the irregular platform on the northern tip of the spur above the river, although there is a more a more amenable location on the south side of the motte, where a level area is sheltered by the rocky ridge. A little to the south a small bank cuts across the ridge. This was probably a hedge bank and may be comparatively recent.

The identification of Domen Las as Abereinion castle by Wiles and others is interesting and muddies the waters more than somewhat.  The River Einion flows into the Dovey very near Domen Las but there is also a River Einion to the south, and in The Welsh Chronicle it is listed as having been built by Malgwn in 1205 and is sometimes identified with the mound at Cil y Graig in Cardigan as Abereinion Castle.  It is entirely possible, of course, that both names were applied to the same castle.  If that were the case, the Domen Las site is the most plausible location as it is both at the mouth of the river Dovey, where it spreads into the estuary, and at the mouth of the river Einion, where it joins the Dovey.

Another candidate for Abyerdyfi Castle is Tomen Las near Pennal.  This is actually within Gwynedd with clear views over the estuary to Ceredigion and to Domen Las.  At the south of Gwynedd, near the borders with Deheubarth, this is yet another plausible site.  The Coflein website suggests that it was a former court (llys) of the princes of Pennal and describes the surviving remains as a circular mound 26m in diameter that rises 3.0m from the traces of its ditch with a level summit 15-17m across. There are no traces of further earthworks.

The short answer to the question posed in the title of this post is that there is no definitive location for Aberdyfi Castle. I have searched for but failed to find any records that the Pen-y-Bryn or Domen Las sites have been excavated, but it would certainly be interesting if future research into the question were to extend beyond analysis of the late Medieaval texts and into the field.  If I had to put money on it, I would go for the Domen Las site, mainly because of the political significance of the location just over the border of Gwynedd in Ceredigion, a good location from which to make a statement about the dominance of  Llewelyn ab Iowerth over both Gwynedd and the Deheubarth territories to its south.

Finally, returning to Pen-y-Bryn, a booklet by the Aberdyfi Chamber of Trade says that the castle on the hill was built by Rhys ap Gruffydd in 1151, when it was called Bryn Celwydd and was destroyed in 1157 by the Norman Earl Robert de Clare.  The little shelter at its top was a gift from a local landowner in 1897.  It can be approached from a footpath on the left as you head up Copper Hill Street, or from the seafront road just on the town side of the railway bridge, along a track that has recently been restored after several years of closure.  It looks as though you are heading into someone’s garden, but the steps that lead up on the far right are part of the footpath.  From the shelter there are beautiful views over the Dovey estuary and Cardigan Bay.

References

Aberdyfi Chamber of Commerce 2003.  Aberdyfi Aberdovey Walks.
Davies, J. 2007 (revised edition of the 1990 and 1992 editions). A History of Wales.  Penguin
Jenkins, G.H. 2007.  A Concise History of Wales.  Cambridge University Press
Lewis, H. M. 2001. Aberdyfi: The past Recalled. Dinas
Turvey, R. 1997. The Lord Rhys: Prince of Deheubarth. Gomer.
Wiles, J. 2008.  Domen Las or perhaps Abereinion Castle. Coflein. http://www.coflein.gov.uk/en/site/303600/details/domen-las-or-perhaps-abereinion-castle