As administrator of the Diocese of Hereford, he was involved in fighting against the Welsh, suffering two defeats at the hands of raiders before securing a settlement with Gruffydd ap Llywelyn, a Welsh ruler.

This was in retaliation for a raid led by the Welsh rulers Gruffydd ap Rhydderch, Rhys ap Rhydderch, and Gruffydd ap Llywelyn.

Tension also grew across North Wales, where opposition to the 1211 treaty between John and Llywelyn was turning into open conflict.

John put off dealing with the badly deteriorating situation in North Wales, where Llywelyn the Great was leading a rebellion against the 1211 settlement.

Glyndŵr was a descendant of the Princes of Powys from his father Gruffydd Fychan II, hereditary Tywysog of Powys Fadog and Lord of Glyndyfrdwy, and of those of Deheubarth through his mother Elen ferch Tomas ap Llywelyn.

Rhys eventually became the main power in Deheubarth, but never ruled more than a portion of his father's realm and was a client prince of Llywelyn the Great of Gwynedd.

Henry yielded, and the favourites were dismissed, Hubert de Burgh ( whom they had imprisoned ) was released and reconciled to the king and soon the archbishop was sent to Wales to negotiate peace with Prince Llywelyn the Great.

His grandson Llywelyn the Great is not known to have used the title ' Prince of Wales ' as such, although his use, from around 1230, of the style ' Prince of Aberffraw, Lord of Snowdon ' was tantamount to a proclamation of authority over most of Wales, and he did use the title ' Prince of North Wales ' as did his predecessor Dafydd ab Owain Gwynedd.

In 1240, the title was theoretically inherited by his son Dafydd ap Llywelyn, though he is not known to have used it.

In 1282, Llywelyn was killed during Edward I of England's invasion of Wales, possibly by Sir Anthony de Tipton, who was knighted by the King of England afterward, and although his brother Dafydd ap Gruffudd succeeded to the Welsh princeship, issuing documents as prince, his principate was not recognised by the English Crown.

The first was Madog ap Llywelyn, a member of the house of Gwynedd, who led a nationwide revolt in 1294-5, defeating English forces in battle near Denbigh and seizing Caernarfon Castle.

In the 1370s, Owain Lawgoch, an English-born descendant of one of Llywelyn ap Gruffudd's brothers, claimed the title of Prince of Wales, but was assassinated in France in 1378 before he could return to Wales to claim his inheritance.

Support for Llywelyn was weak among his own countrymen.

The Welsh advances ended on 11 December, however, when Llywelyn was lured into a trap and killed at the Battle of Orewin Bridge.

In 1056, the area was devastated by the Welsh prince Gruffydd ap Llywelyn, on his way with an army of Welsh, Saxons and Danes to defeat Ralph, Earl of Hereford and sack the Saxon burh at Hereford, to the north.

Gruffydd ap Llywelyn was the next ruler to be able to unite most of the Welsh kingdoms under his rule.

Powys also had a strong ruler at this time in Madog ap Maredudd, but when his death in 1160 was quickly followed by the death of his heir, Llywelyn ap Madog, Powys was split into two parts and never subsequently reunited.

Out of the power struggle in Gwynedd eventually arose one of the greatest of Welsh leaders, Llywelyn ab Iorwerth, also known as Llywelyn Fawr ( the Great ), who was sole ruler of Gwynedd by 1200 and by his death in 1240 was effectively ruler of much of Wales.

He was probably born at Dolwyddelan though not in the present Dolwyddelan castle, which was built by Llywelyn himself.

Plans were probably first made to construct the castle in 1284, but this was delayed due to lack of funds and work only began in 1295 following the Madog ap Llywelyn uprising.

Following Dafydd's marriage, Llywelyn appears to have started a second phase of building at Dolbadarn, probably in the 1240s, adding these elements to the existing castle.

Llywelyn went to considerable lengths to strengthen Dafydd's position, probably aware that there would be considerable Welsh support for Gruffydd against the half-English Dafydd.

The Pope welcomed the fact that Llywelyn was abolishing this custom.

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.

By 1276 Llywelyn had been declared a rebel by the new King Edward I who was determined to be the master of the whole island of Great Britain.

Indeed the castle at Dolforwyn Castle near Newtown ordered to be built by Llywelyn around the same time has some similarities to Dinas Brân and may have been the work of the same master mason.

In 1055 Gruffydd ap Llywelyn established himself as the ruler of all Wales, and allied himself with Ælfgar of Mercia, who had been outlawed for treason.

Llywelyn was forced to seek terms and to give up all lands east of the River Conwy, but was able to recover them the following year in alliance with the other Welsh princes.

Elise ap Madog, lord of Penllyn, had refused to respond to Llywelyn's summons to arms and was stripped of almost all his lands by Llywelyn as punishment.

In 1211 John invaded Gwynedd with the aid of almost all the other Welsh princes, planning according to Brut y Tywysogion " to dispossess Llywelyn and destroy him utterly ".

Joan was able to persuade her father not to dispossess her husband completely, but Llywelyn lost all his lands east of the River Conwy.

Innocent released Llywelyn, Gwenwynwyn and Maelgwn from all oaths of loyalty to John and lifted the interdict in the territories which they controlled.

Llywelyn was able to recover all Gwynedd apart from the castles of Deganwy and Rhuddlan within two months in 1212.

Llywelyn had now established himself as the leader of the independent princes of Wales, and in December 1215 led an army which included all the lesser princes to capture the castles of Carmarthen, Kidwelly, Llanstephan, Cardigan and Cilgerran.

John Edward Lloyd gave the following assessment of Llywelyn: Among the chieftains who battled against the Anglo-Norman power his place will always be high, if not indeed the highest of all, for no man ever made better or more judicious use of the native force of the Welsh people for adequate national ends ; his patriotic statemanship will always entitle him to wear the proud style of Llywelyn the Great.

Llywelyn and Joan had three identified children in the records but in all probability had more as Llywelyn children were fully recognise during his marriage to Joan whilst his father in law King John was alive.

He is considered to be the most successful of all the north Welsh princes prior to his grandson, Llywelyn the Great.

Dafydd's nemesis proved to be his nephew Llywelyn ap Iorwerth, born most likely in the year 1173 and therefore only a child when all these events were played out.

Llywelyn was forced to seek terms and to give up all his lands east of the River Conwy, but was able to recover these lands the following year in alliance with the other Welsh princes.

Between 1255 and 1258 Llywelyn orchestrated a campaign against England across all of Wales gaining allies in Deheubarth and Powys.

A confined Llywelyn appears to have put all of his hopes into stabilising the succession through children sired by his new wife Eleanor de Montfort.

The remaining important members of the ruling house were all arrested and imprisoned for the remainder of their lives ( Dafydd's sons Llywelyn ap Dafydd and Owain ap Dafydd in Bristol Castle, his daughters and niece in convents ).

Ednyfed Fychan, 13th century seneschal to Llywelyn the Great and ancestor to the House of Tudor was granted the land and built a castle on the hill, of which all traces have disappeared, and a manor, Llys Euryn of which the ruins of its 15th century reconstruction can be seen today.

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.

As Llywelyn then captured and held all the territory from the River Arth to the River Aeron, he conferred Dinerth on the sons of Maelgwn's brother Gruffudd as was rightfully due.

Its predecessors have all been variations on either the Red Dragon, an ancient emblem revived by Henry VII, or the arms of Llywelyn.