The rebel prince: why 16th September belongs to Owain Glyndŵr
Every year on 16th September, buildings, castles, and streets across Wales fly a striking red-and-gold flag featuring four fierce lions. This is Owain Glyndŵr Day (Diwrnod Owain Glyndŵr), a national celebration honouring the legendary leader who staged the final, most spectacular rebellion for Welsh independence.
The spark of rebellion: 16th September 1400
In the late 14th century, Owain Glyndŵr was not a rugged outlaw, but a well-educated, wealthy Welsh nobleman. He had studied law in London and served with distinction in the English military.
Tension, however, was was brewing. A bitter land dispute with his powerful English neighbour, Reginald de Grey, boiled over when the newly crowned King Henry IV of England ignored Glyndŵr's legal appeals. Realising that Welsh citizens could not find justice under the English crown, Glyndŵr chose a radical new path.
On 16th September 1400, a small, intense group of Welsh nationalists gathered at Glyndŵr's estate in Glyndyfrdwy. There, they took a treasonous step: they boldly proclaimed Owain Glyndŵr the Prince of Wales.
Within days, this act of defiance transformed into a nationwide guerrilla war. Glyndŵr captured English strongholds, established the first Welsh parliament in Machynlleth, and forged international alliances with France and Scotland. For a brief, shining moment, an independent Wales was a reality.
The banners of a prince: the flags of Glyndŵr
When Owain Glyndŵr is celebrated today, we will inevitably see two iconic banners that struck fear into the hearts of medieval English armies.
The banner of Arms (the four lions)
This is the most recognizable flag associated with Glyndŵr. It features a quarterly design comprising four lions rampant (standing on their hind legs)—two red lions on gold squares, and two gold lions on red squares. This flag was a masterful piece of political branding. By combining the heraldry of the ancient royal houses of Powys (his father's side) and Deheubarth (his mother's side), Glyndŵr visually declared his legitimate bloodright to rule all of Wales.
Today the flag serves as a modern symbol of Welsh patriotism, pride, and national identity.
Y Ddraig Aur (the Golden Dragon)
Before the modern red dragon (Y Ddraig Goch) became the official standard of Wales, Glyndŵr rode into battle under a different beast - a blazing golden dragon emblazoned on a white background.
Glyndŵr deliberately invoked the prophecies of Merlin and the legends of Uther Pendragon (King Arthur's father) and by raising the Golden Dragon—most famously over Caernarfon in 1401—he was telling his followers that the ancient, prophesied deliverer of Wales had finally arrived.
By 1410, the rebellion began to fracture under the weight of English blockades and military might. Yet, unlike many medieval rebels, Glyndŵr was never captured. He was never betrayed by his people, despite massive rewards offered for his head.
Instead, around 1415, he simply vanished into the mist of the Welsh mountains, refusing royal pardons even on his deathbed. Because his final resting place remains a total mystery, Glyndŵr achieved a mythic status akin to King Arthur—a sleeping hero who will return when his country needs him most.
Every 16th September, when those red and gold flags catch the autumn wind, Wales remembers the prince who refused to bow.
