During the rebellion's height between 1403 and 1406, Owain exercised control over the majority of Wales after capturing several of the most powerful English castles in the country, and formed a parliament at Machynlleth.

The uprising began in 1400, when Owain Glyndŵr, a descendant of several Welsh royal dynasties, claimed the title prince of Wales following a dispute with a neighbouring English lord.

In 1404, after a series of successful castle sieges and battlefield victories, Owain was crowned prince of Wales in the presence of Scottish, French, Spanish and Breton envoys.

He ignored two offers of a pardon from the new King Henry V and Welsh resistance continued in small pockets of the country for several more years utilising guerrilla tactics.

In the last decade of the 14th century, Richard II of England had launched a bold plan to consolidate his hold on his kingdom and break the power of the magnates who constantly threatened his authority.

Richard died in Pontefract Castle, shortly after the failed Epiphany Rising of English nobles in January 1400, but his death was not generally known for some time.

[3][better source needed] Successive holders of the title Baron Grey de Ruthyn of Dyffryn Clwyd were English landowners in Wales.

[5] Another story is that de Grey deliberately withheld a Royal Summons for Glyndŵr to join the new king's Scottish campaign of August 1400.

On 16 September 1400, Owain acted, and was proclaimed Prince of Wales by a small band of followers who included his eldest son, his brothers-in-law, and the Dean of St Asaph.

[14] Rhys ap Tudur led an ambush of the king's forces at a place called Rhos Fawr ('the Great Moor').

[16] Most of the country agreed to pay all the usual taxes, but the Tudurs knew that they needed a bargaining chip if they were to lift the dire threat hanging over them.

Although the Conwy Castle garrison amounted to just fifteen men-at-arms and sixty archers, it was well stocked and easily reinforced from the sea; and in any case, the Tudurs only had forty men.

On Good Friday, 1 April, all but five of the garrison were in the little church in the town when a carpenter appeared at the castle gate, who, according to Adam of Usk's Chronicon, "feigned to come for his accustomed work".

[12] When Percy arrived from Denbigh with 120 men-at-arms and 300 archers, he knew it would take a great deal more to get inside so formidable a fortress and was forced to negotiate.

The English saw that if the revolt prospered it would inevitably attract disaffected supporters of the deposed King Richard, rumours of whose survival were widely circulating.

[20][21] The laws included prohibiting any Welshman from buying land in England, from holding any senior public office in Wales, from bearing arms, and from holding any castle or defending any house; no Welsh child was to be educated or apprenticed to any trade, no Englishman could be convicted in any suit brought by a Welshman, Welshmen were to be severely penalised when marrying English women, any Englishman marrying a Welsh woman was disenfranchised, and all public assembly was forbidden.

In June 1402, Owain's forces encountered an army led by Sir Edmund Mortimer, the uncle of the Earl of March, at Bryn Glas in central Wales.

The battle lasted all day, Prince Henry was badly wounded in the face by an arrow but continued to fight alongside his men.

[27] Anxious to demonstrate his seriousness as a ruler, he held court at Harlech and appointed the deft and brilliant Gruffydd Young as his chancellor.

Owain demonstrated his new status by negotiating the "Tripartite Indenture" in February 1405 with Edmund Mortimer and Henry Percy the 1st Earl of Northumberland.

It was rumoured that old allies of Richard II were sending money and arms to the Welsh and the Cistercians and Franciscans were funneling funds to support the rebellion.

John ap Hywel, Abbot of the nearby Llantarnam Cistercian monastery, was killed during the Battle of Usk as he ministered to the dying and wounded on both sides.

In March, 1,000 men from all over Flintshire appeared before the Chief Justitiar of the county and agreed to pay a communal fine for their adherence to Glyndŵr.

Philip Scudamore and Rhys ap Tudur were also beheaded and their heads displayed at Shrewsbury and Chester (no doubt to discourage any further thoughts of rebellion).

In 1412, Owain captured, and later ransomed, a leading Welsh supporter of King Henry's, Dafydd Gam ("Crooked David"), in an ambush in Brecon.

As late as 1414, there were rumours that the Herefordshire based Lollard leader, Sir John Oldcastle, was communicating with Owain and reinforcements were sent to the major castles in the north and south.

[29] There is some evidence to suggest, in the poetry of the Welsh Bard Llawdden for example, that a few diehards continued to fight on even after 1421 under the leadership of Owain's son-in-law Phylib ap Rhys.

As late as 1492, a Royal Official in lowland Glamorgan was still citing the devastation caused by the revolt as the reason he was unable to deliver promised revenues to the King.

For many years after his surrender and despite official proscriptions, he sheltered rebels on the run, levied fines on 200 individuals that had not supported him, rode around the county with his retinue, and even plotted the murder of the King's justice.

[32] However, there were several occasions where Welshmen were granted the legal status of Englishmen, such as Edmund and Jasper Tudor, the half brothers of Henry VI of England.