However, when Henry II returned to England he found that the war had already begun, with Owain's son Dafydd raiding Angevin positions in Tegeingle, exposing the castles of Rhuddlan and Basingwerk to " serious dangers ", wrote Lloyd.

This marriage was not considered valid by the church as Cristin was Owain's first cousin, a degree of relationship which according to Canon law prohibited marriage.

Rhun was Owain's favourite son, and his premature death in 1147 plunged his father into a deep melancholy, from which he was only roused by the news that his forces had captured Mold castle.

Still, Gwalchmei was clearly a traditional figure ; other early references to him include the Welsh Triads ; the Englynion y Beddau ( Stanzas of the Graves ), which lists the site of his grave ; the Trioedd y Meirch ( Triads of the Horses ), which praises his horse Keincaled ( known as Gringolet to later French authors ); and Cynddelw's elegy for Owain Gwynedd, which compares Owain's boldness to that of Gwalchmei.

Peace between the brothers held until 1147, when an unrecorded event occurred which led Owain's sons Hywel and Cynan to drive Cadwaladr out of Meirionydd and Ceredigon, with Cadwaladr retreating to Môn.

Hywel ab Owain Gwynedd duly succeeded his father in 1170 and the realm was plunged immediately into a civil war that appears to have been a conflict between two rival factions ; one which was pro-Irish and seeking to ensure the succession of Hywel and protect the legacy of Owain Gwynedd and his father, and a second which seems to be an anti-Irish coalition and headed by Iorwerth Drwyndwn and Owain's widow, Cristin ferch Goronwy ab Owain.

The Norman lords, the Justiciar of Salop, and at least one bishop, bribed Owain's Welsh enemies to attack him and his father, which they promptly did.

Peace between the brothers held until 1147, when an unrecorded event occurred which led Owain's sons Hywel and Cynan to drive Cadwaladr out of Meirionydd and Ceredigion, with Cadwaladr retreating to Môn.

The speed with which Cristen and her sons acted suggest that the conspiracy may have had roots before Owain's death.

Lamb gained Owain's confidence and became his chamberlain, which gave him the opportunity to stab Owain to death in July 1378.

The bard Iolo Goch (" Red Iolo "), himself a Welsh lord, visited him in the 1390s and wrote a number of odes to Owain, praising Owain's liberality, and writing of Sycharth, " Rare was it there / to see a latch or a lock.

However, apart from a small melee at the Battle of Crogen there was little fighting, for the Welsh weather came to Owain's assistance as torrential rain forced Henry to retreat in disorder.

The infuriated Henry mutilated a number of Welsh hostages, including two of Owain's sons.

His chronicle records the ' Welsh Revolt ', in 1403, when Owain Glyndŵr burned Usk to the ground while gaining control of much of South Wales from the English under King Henry IV and his son, later to become King Henry V. The important Battle of Pwll Melyn in 1405 occurred immediately north of Usk Castle, when English forces routed their Welsh opponents, causing much loss of life, including that of Owain's brother Tudur.

Warwick engaged Welsh forces at the Battle of Mynydd Cwmdu, near Tretower Castle a few miles northwest of Crickhowell – nearly capturing Owain Glyndwr himself, taking Owain's banner, forcing the Welsh to flee.

Owain followed a diplomatic policy of binding other Welsh rulers to Gwynedd through dynastic marriages, and Cadwaladr's border dispute and murder of Anarawd threatened Owain's efforts and credibility.

In frustration, Henry II had twenty-two Welsh hostages mutilated ; the sons of Owain ' supporters and allies, including two of Owain's own sons.

In fact, Owain had a brother, but not a son, named Einion, and Welsh geneaologies do not name the mother of Owain's son Llywelyn.

During Owain's reign he chose to change his title from King of Gwynedd to Prince of the Welsh ( J.

Owain followed a diplomatic policy of binding other Welsh rulers to Gwynedd through dynastic marriages, and Cadwaladr's border dispute and murder of Anarawd threatened Owain's efforts and credibility.

Between 1148 and 1151, Owain I of Gwynedd fought against Madog ap Maredudd of Powys, Owain's son-in-law, and against the Earl of Chester for control of Iâl, with Owain having secured Rhuddlan Castle and all of Tegeingl from Chester.

Owain's strategy was in sharp contrast to Rhys ap Gruffydd, prince of Deheubarth, who in 1162 rose in open revolt against the Normans in south Wales, drawing Henry II back to England from the continent.

Owain's forces allegedly attacked it in either 1401 or 1403, capturing the garrison of sixty men inside, whom he then hanged from the curtain walls over the battlements, then beheaded and buried nearby.

Owain's sons were either taken prisoner or died in battle and had no issue.

There is no record of Iorwerth having taken part in the power struggle between some of Owain Gwynedd's other sons following Owain's death, although he was the eldest surviving son.

While Taliesin certainly outlived Owain, as demonstrated by a lament he composed for Owain's death, there is no proof that he survived Urien.

Owain's father tried to persuade him to return Nest, but to no avail.

After a number of initial confrontations between King Henry IV and Owain's followers in September and October 1400, the revolt began to spread in 1401.

In response, Mortimer negotiated an alliance with Owain and married one of Owain's daughters.

By 1407 this strategy was beginning to bear fruit, even though by this point Owain's rebel soldiers had concluded successful battles with the King ’ s men as far as Birmingham, where the English were in retreat.

However, with Owain's eye off the real prize — the independence of Wales, one by one the lordships began to surrender.

Owain's daughter, Alys, had married, secretly, Sir John Scudamore, the King's appointed Sheriff of Herefordshire.

After Owain's death, there was little resistance to English rule until, in the 16th century, the Tudor dynasty, whilst allowing Welshmen to become more prominent in English society, saw Owain's revolt as a catastrophe for Wales.

It was not until the late 19th century that Owain's reputation was revived.

The discovery of Owain's Great Seal and his letters to the French in the Bibliothèque Nationale helped revise historical images of him as a purely local leader.

The threatened invasion did not take place, and Turvey suggests that Owain's intention may have been to test the resolve of the new ruler.

The earls were assisted by Cadwaladr, brother of Owain Gwynedd, and Owain's sons, Hywel and Cynan.

Owain's father, Gruffudd ap Cynan, was a strong and long-lived ruler who had made the principality of Gwynedd the most influential in Wales during the sixty-two years of his reign, using the island of Anglesey as his power base.

Henry invaded Gwynedd in 1157 with the support of Madog ap Maredudd of Powys and Owain's brother Cadwaladr.

Owain's men ambushed the royal army in a narrow, wooded valley, routing it completely with King Henry himself narrowly avoiding capture.

The last years of Owain's life were spent in disputes with the Archbishop of Canterbury, Thomas Becket, over the appointment of a new Bishop of Bangor.

The dispute continued, and the see remained officially vacant until well after Owain's death.

Dafydd and Rhodri split Gwynedd between them, but a generation passed before Gwynedd was restored to its former glory under Owain's grandson Llywelyn the Great.