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.

Owain took advantage of the civil war in England between King Stephen and the Empress Matilda to push Gwynedd's boundaries further east than ever before.

By about 1118 Gruffudd's advancing years meant that most of the fighting which pushed Gwynedd's borders eastward and southwards was done by his three sons by his wife Angharad, daughter of Owain ab Edwin: Cadwallon, Owain Gwynedd and later Cadwaladr.

Of the first three, only Cadell reigned for more than a few years, but the youngest of the four, Rhys ap Gruffydd ( The Lord Rhys ), ruled from 1155 to 1197, and after Owain Gwynedd's death in 1170 made Deheubarth the most powerful of the Welsh kingdoms.

While Owain ap Cadwgan of Ceredigion sought refuge in Gwynedd's mountains, Maredudd ap Bleddyn of Powys made peace with the English king as the Norman army advanced.

For the remainder of his life, while Gruffydd I continued to rule in Gwynedd, his sons Cadwallon, Owain, and Cadwaladr, would lead Gwynedd's army after 1120.

Owain, however, did not participate in the battle, keeping the majority of Gwynedd's army at home.

The death of Madog ap Meredudd of Powys in 1160 opened an opportunity for Owain I of Gwynedd to further press Gwynedd's influence at the expense of Powys.

However, Owain continued to further Gwynedd's expansion without rousing the English crown, maintaining his ' prudent policy ' of Quieta non movere ( don't move settled things ), as Lloyd wrote.

Madog is referred to as " Splendid Madog ... / Of Owain Gwynedd's line, / He desired not land ... / Or worldy wealth but the sea.

By 1200 Owain Gwynedd's grandson Llywelyn Fawr ( the Great ) ap Iorwerth ruled over all of Gwynedd, with England endorsing all of Llywellyns holdings that year.

Rhys was one of the most successful and powerful Welsh princes, and after the death of Owain Gwynedd of Gwynedd in 1170 was the dominant power in Wales.

The departure of the Norman lords enabled Rhys to strengthen his position, and the death of Owain Gwynedd in late 1170 left him as the acknowledged leader of the Welsh princes.

Owain followed his father on the throne of Gwynedd the following year and ruled until his death in 1170.

During Llywelyn's boyhood, Gwynedd was ruled by two of his uncles, who split the kingdom between them, following the death of Llywelyn's grandfather, Owain Gwynedd, in 1170.

Llywelyn was born about 1173, the son of Iorwerth ap Owain and the grandson of Owain Gwynedd, who had been ruler of Gwynedd until his death in 1170.

Since the death of Owain Gwynedd in 1170, Rhys ap Gruffydd had made the southern kingdom of Deheubarth the strongest of the Welsh kingdoms, and had established himself as the leader of Pura Wallia.

Owain Gwynedd ap Gruffydd (; 1100 – 28 November 1170 ) was King of Gwynedd from 1137 until his death in 1170, and the first to be known as Prince of Wales.

On Gruffydd's death in 1137, therefore, Owain inherited a portion of a well-established kingdom, but had to share it with Cadwaladr.

Owain then designated Hywel ab Owain Gwynedd as his successor, but after his death Hywel was first driven to seek refuge in Ireland by Cristina's sons, Dafydd and Rhodri, then killed at the battle of Pentraeth when he returned with an Irish army.

Taliesin may or may not have served Owain mab Urien following Urien's death, as the chronology is not entirely clear.

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

One poem, a " marwnad " or death lament, was addressed to Owain, son of Urien.

He was a grandson of Owain Gwynedd and ruled southern Powys from 1195, having taken control following the death of his father Owain Cyfeiliog.

Other days which have been proposed for national public commemorations are 16 September ( the day on which Owain Glyndŵr's rebellion began ) and 11 December ( the death of Llywelyn the Last ).

When word reached Gwynedd of Gwenllain's death and the revolt in Gwent, Gruffydd I's sons Owain and Cadwaladr invaded Norman controlled Ceredigon, taking Llanfihangle, Aberystwyth, and Llanbadarn.

Owain returned to Gwynedd-he apparently " escaped " or was released from Chester immediately after the news of Dafydd's death reached England.

While the Gwentian Chronicle records that " Einion son of Owain was slain " in 982 in " Gorwennydd where the action of Pencoed Colwyn took place " 11 However, Gorfynnydd, which may be a form of Gorennydd, is recorded as part of the Kingdom of Glywysing, which on Glywysing's death was given to one of the old king's son, as were 6 other cartrefi including Cydweli and Gywr, which suggests that Gorfynnydd was close by and if Einon did battle there, it is even more possible that he may have died at Cor Einon tryin to return to his stronghold at Llys Nini.

* 1170 Assassination of Thomas a Becket ; death of Owain Gwynedd, prince of Wales

In addition to this, the final defeat of the uprising led by the Welsh prince, Owain Glyndŵr, in 1412 by Prince Henry ( who later became Henry V ) represents the last major armed attempt by the Welsh to throw off English rule.

These events led to Owain being proclaimed Prince of Wales on 16 September 1400, by a small band of followers which included his eldest son, his brothers-in-law, and the Dean of St Asaph in the town of Corwen, possibly in the church of SS Mael & Sulien.

In 1412, Owain led one of the final successful raiding parties with his most faithful soldiers and cut through the King ’ s men, and consequently captured, and later ransomed, a leading Welsh supporter of King Henry's, Dafydd Gam (" Crooked David "), in an ambush in Brecon.

Gruffydd formed an alliance with Gwynedd, and later in 1136 the sons of Gruffudd ap Cynan, Owain Gwynedd and Cadwaladr ap Gruffydd, led an army to Ceredigion.

Warren suggests that when Rhys and Owain were obliged to do homage to Henry in 1163 they were forced to accept a status of dependent vassalage instead of their previous client status, and that this led to the revolt.

He was met by the united forces of the Welsh princes, led by Owain Gwynedd and including Rhys.

Less than three years later, Henry was in command of part of the English forces — he led his own army into Wales against Owain Glyndŵr and joined forces with his father to fight Harry Hotspur at Shrewsbury in 1403.

The Welsh launched several revolts against English rule, the last significant one being that led by Owain Glyndŵr in the early 15th century.

* Glyndŵr Rising in Wales ( 1400 – 1415 ), led by Owain Glyndŵr.

King Henry IV defeats a rebel army led by Henry Hotspur Percy who has allied with the Welsh rebel Owain Glyndŵr.

By about 1120 Gruffydd had grown too old to lead his forces in battle and Owain and his brothers Cadwallon and later Cadwaladr led the forces of Gwynedd against the Normans and against other Welsh princes with great success.

The precarious position of Normans and Flemings was demonstrated in 1136 when the Normans, having already lost 500 men in battle at Loughor, re-recruited from Lordships from all over South Wales and led by Robert fitz Martin at Crug Mawr near Cardigan attacked Owain Gwynedd and his army.

In 1400 a revolt broke out in North Wales against English rule, led by Owain Glyndŵr.

In 1400 a revolt broke out in North Wales against English rule, led by Owain Glyndŵr.

The English invasion faced an alliance of Welsh princes led by King Owain Gwynedd, but there was little fighting – endless days of heavy rain forced the army to retreat.

Soon after reaching his majority and taking responsibility for the Earldom, he saw military action in Wales, defending against a Welsh rebellion led by Owain Glyndŵr.

Owain expanded his international diplomatic offensive against Henry II by sending an embassy to Louis VII of France in 1168, led by Arthur of Bardsey, Bishop of Bangor ( 1166 – 1177 ), who was charged with negotiating a joint alliance against Henry II.

A final rebellion in 1400 led by Owain Glyndŵr, a member of the rival royal house of Powys, also drew considerable support from within Gwynedd.

Corwen is best known for its connections with Owain Glyndŵr, the early fifteenth century Welsh prince who led the Welsh in their struggle for independence.

The castle was refortified on the Royal command of new King King Henry IV in 1400 and carried out by Sir John Pauncefote, great grandson of Sir Grimbold, in advance of the uprising led by Owain Glyndŵr to 1412.

A field in the neighbouring forest of Kingswood, Maes Gwenllian is known as the location of a battle in 1136, in which Princess Gwenllian, sister of Owain Gwynedd, led her husband's troops into battle against a Norman army during his absence.

There was a resurgence of interest in Clun Castle during the Glyndŵr Rising of 1400 – 15, with Thomas playing a key role in suppressing the revolt ; the castle was refortified and saw some service against the Welsh rebels led by Owain Glyndŵr.

During the national uprising led by Owain Glyndŵr, the Welsh took possession of the castle in 1404.

The same year, Owain Gwynedd led the defeat of the Norman rulers in the town of Cardigan at the Battle of Crug Mawr.