The Battle of Mynydd Hyddgen took place between the Welsh and English in June 1401. It was the first major victory by Owain Glyndà µr of the Welsh Revolt of 1400âÂÂ1409. Its location was on the western slopes of Plynlimon, near the Ceredigion/Powys boundary. Glyndà µr, defending with a much smaller force, routed an attack of English and Flemish settlers and soldiers at a site on or close to Mynydd Hyddgen, a peak in the Ceredigion uplands.
The battle was significant in giving new impetus to the nascent rebellion, and provoking a punitive response from the English King, Henry IV. It is likely that Glyndà µr utilised the local geography to his advantage, perhaps drawing the forces into a trap using the natural draw of the land where a spring rises, buttressed by natural rock ramparts, although no confirmatory accounts of the battle exist, and the exact location is uncertain.
The Welsh Revolt began in 1400 when Owain Glyndà µr found himself in dispute with English earls, and the king refused to support him. He was proclaimed Prince of Wales by his followers in September that year, and various skirmishes ensued, orchestrated both by himself and by Rhys ap Tudur and Gwilym ap Tudur in North Wales. Henry IV, king of England, attempted to diffuse tensions by offering peace to all rebels except these three perpetrators, but by May of 1401 the King issued a royal commission owing to the real threat from Glyndà µr, who was assembling forces in Carmarthen and threatening the English realm in Pembrokeshire (a location known as Little England Beyond Wales). Initially Glyndà µr saw two set backs in North Wales, defeated at Mawddwy and Cader Idris, before he moved to a location on the slopes of Pumlumon in the Ceredigion uplands.
The sole authority for the battle is found in the fifteenth century Annales Oweni Glyndwr, a Welsh chronicle possibly written as early as 1422 or later up to the 1450s but later copied by Gruffydd Hiraethog many years later in 1550. This reads (in translation from Latin):
<blockquote> "The next summer after that, Owain rose up with six score wicked men and thieves, and he brought them as to war into the uplands of Ceredigion. And fifteen hundred men from the lowland of Ceredigion and Rhos and Pembroke assembled there and they came to the mountain to try to capture Owain. And on Hyddgant Mountain was the encounter between them, and as soon as the English host turned their backs to flee, two hundred of them were killed. And then great praise came to Owain, and there rose up with him a great part of the youth and the wicked men from every region of Wales until there was a great host with him." </blockquote>
Some historians have raised doubts as to whether this battle happened as per the above account, noting the lack of corroborative evidence in muster roles, records of payments or other accounts. Yet Historians agree that this battle explains a deterioration in the security situation in Wales, and the sudden change of posture from Henry IV towards the rebellion, lending credence to a significant victory for Glyndà µr.
The English forces comprised Anglo-Fleming settlers from West Wales. The settler lands had previously been pillaged by Glyndà µr, so the force gathered to oppose Glyndà µr in his Mid Wales stronghold. The settlers were reinforced by a large force of English soldiers and Flemish mercenaries. Historians have doubted the relative size of the forces of ten to one, although there would have been several hundred in the Anglo-Flemish force. Alternatively, the author and antiquarian, Thomas Owen Morgan, proposed that the 120 in Glyndà µr's forces were supplemented by archers at a typical rate at the time of three to one, giving approaching 500 on his side. This number has been adopted by some later accounts. In any case, Glyndà µr is described as heavily outnumbered. Writers following Morgan's thesis, propose Glyndà µr's force would have been made up mostly of archers mounted on hill ponies that would have been well suited for travelling across boggy or mountainous regions.
The Anglo-Flemish army meanwhile would have probably consisted of infantry with some light cavalrymen supporting them. Despite having decent equipment, the English-Flemish soldiers lacked military experience, and their rout may suggest a general lack of discipline within their army, although an alternative proposal is that they succumbed to a flanking tactic.
The precise location of the battle is not known, and little is known of the course of the battle. Mynydd Hyddgen lies between the Hyddgen and Hengwm rivers in the Ceredigion uplands of Elenydd. The rivers meet at the southern end of the mountain ( means "mountain" in Welsh). One tradition places the battle close to the Hyddgen river, and associated with two white quartz blocks on the opposing bank, to the south of the summit, known as Glyndà µr's Covenant Stones. A battle at the summit is also possible, but across the Hyddgen river from the Covenant Stones lies an exposed knee of rock, . A spring creates a natural draw up this slope, and a commanding view across both river valleys and unimpeded sight lines across the Elenydd uplands to the south. The attack came from the south, and as the location is strategically superior to the alternatives, and in sight of the Covenant Stones, this has also become a proposed location of the battle.
There is no detailed account of the battle. It is known that Glyndà µr's army was able to fight back these attackers (despite being outnumbered and on the low ground), killing 200, chasing the main force away and taking prisoners from the rest. Owain's success may have laid in the maneuverability of his light troops. The English army (being more heavily laden) would have had more trouble traversing the marshy ground of the valley, and Glyndà µr's forces had ponies able to do so.
Another theory is proposed by historian Michael Livingston. He surveyed the proposed battle location of Banc Lluestnewydd and observed a flat area about the size of a sports pitch that lies out of sight from the land below, and on which a reserve force might be concealed. Noting Glyndà µr's known tactics in other battles, and his familiarity with the location, Livingston posits that Glyndà µr may have allowed half his forces to be seen on the low land, perhaps near the covenant stones, and this force allowed themselves to be pursued up Banc Lluestnewydd. This would account for the historical association of the stones with this battle. The exposed rocks of Banc Lluestnewydd create a natural rampart, and required the pursuit to follow the force, and not encircle them. Then, the reserve force would be able to reveal themselves and close the trap, encircling the English attackers.
This first major victory for Glyndà µr prompted Henry IV to at last take the Welsh Revolt seriously. On 18 September he sent out calls to raise an army at Worcester, seeing the Welsh threat as a clear and present danger. This army then entered Wales to engage with Glyndà µr. Meanwhile the victory gave the rebellion new impetus, and allowed Glyndà µr to move south. He made his way to the Tywi valley, where he was "enthusiastically received". Henry was unable to bring the rebellion to a swift end, failing to engage in more than skirmishes until November saw them engage at Caernarfon in the indecisive Battle of Tuthill. Glyndà µr was also able to open negotiations with the French, Scots and Irish. The Welsh Revolt was not finally brought to an effective end until 1409, and Glyndà µr was never captured.
In 1977 a memorial was erected and unveiled at the Nant y Moch reservoir dam to commemorate the battle and to remember those killed. The memorial was unveiled by Gwynfor Evans, Member of Parliament for Carmarthenshire and then president of Plaid Cymru.