Llywelyn the Great's other son, Gruffudd had been killed trying to escape from the Tower of London in 1244.

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.

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 ".

The other Welsh princes, who had supported King John against Llywelyn, soon became disillusioned with John's rule and changed sides.

Llywelyn called up the other princes for a campaign against him and drove him out of southern Powys once more.

Until 1230 Llywelyn had used the title princeps Norwalliæ ' Prince of North Wales ', but from that year he changed his title to ' Prince of North Wales and Lord of Snowdonia ', possibly to underline his supremacy over the other Welsh princes.

In 1238 Llywelyn held a council at Strata Florida Abbey where the other Welsh princes swore fealty to Dafydd.

Llywelyn dominated Wales for over forty years, and was one of only two Welsh rulers to be called " the Great ", the other being his ancestor Rhodri the Great.

Notwithstanding his other actions, Peckham's relations with the king were generally good, and Edward sent him on a diplomatic mission to Llywelyn the Last in Wales.

Unlike many other 13th-century Welsh castles, Caerphilly Castle was not built by Edward I in his crack-down on the Welsh lords, but by Gilbert ' the Red ' de Clare, a powerful, red-headed nobleman of Norman descent, as a response to a dispute between him and the Prince of Gwynedd, Llywelyn the Last.

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.

Llywelyn the Great was determined to enforce the right of legitimate sons in Welsh succession law to bring Gwynedd in line with other Christian countries in Europe.

Llywelyn refused to pay homage to the new king, partly because of the military actions of Bohun and other Marcher lords, which Llywelyn saw as violations of the Treaty of Montgomery.

Hereford and the other marcher lords used Llywelyn Bren's death as a symbol of Despenser tyranny.

The Principality of Wales was created in 1216 at the Council of Aberdyfi, when it was agreed between Llywelyn the Great and the other sovereign princes among the Welsh that he was the paramount ruler amongst them, and they would pay homage to him.

This title would be granted to his successor Llywelyn in 1267 ( after a campaign by him to achieve it ) and was later claimed by his brother Dafydd and other members of the princely House of Aberffraw.

Early in 1212 Llywelyn had regained the Perfeddwlad and burned the castle at Ystwyth. Llywelyn's revolt caused John to postpone his invasion of France, and Philip Augustus, the King of France, was so moved as to contact Prince Llywelyn I and proposed they ally against the English king King John ordered the execution by hanging of his Welsh hostages, the sons of many of Llywelyn's supporters Llywelyn I was the first prince to receive the fealty of other Welsh lords with the 1216 Council of Aberdyfi, thus becoming the de facto Prince of Wales and giving substance to the Aberffraw claims.

After various other unsuccessful attacks the castle fell in 1217 but was restored to the English in 1220 as part of the settlement between Llywelyn ap Iorwerth and Henry III of England.

Edward clashed with Llywelyn ap Gruffydd, who directly ruled the Kingdom of Gwynedd while other parts of the Principality of Wales were English-controlled Marcher Lordships existing since Norman times.

In those days great strife was bred at the instigation of the Devil between the sons of Gruffudd ap Llywelyn, Namely Owain Goch and Dafydd on the one side, and Llywelyn on the other.

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.

John took a close interest in Wales and knew the country well, visiting every year between 1204 and 1211 and marrying his illegitimate daughter, Joan, to the Welsh prince Llywelyn the Great.

A major royal expedition to enforce these agreements occurred in 1211, after Llywelyn attempted to exploit the instability caused by the removal of William de Braose, through the Welsh uprising of 1211.

* December 11 – At the Battle of Orewin Bridge in mid-Wales, Llywelyn the Last is killed and the Welsh suffer their final decisive defeat at the hands of the English.

* Owain Goch ap Gruffydd, Welsh nobleman, brother to Llywelyn the Last

** January – Harold II marries Edith, daughter of Ælfgār, Earl of Mercia, and widow of Welsh ruler Gruffydd ap Llywelyn.

* Llywelyn ap Gruffyd is subdued by King Edward I of England in the First Welsh War.

* 1277 – Llywelyn ap Gruffyd is subdued by King Edward I of England in the First Welsh War.

** Llywelyn Bren, Welsh rebel

* Ealdred, Bishop of Worcester, leads troops from England on an unsuccessful punitive raid against Welsh leaders Gruffydd ap Rhydderch, Rhys ap Rhydderch and Gruffydd ap Llywelyn.

About January 1066, Harold married Edith ( or Ealdgyth ), daughter of Ælfgar, Earl of Mercia, and widow of the Welsh prince Gruffydd ap Llywelyn.

* Llywelyn ap Dafydd, a Welsh prince ( in his prison at Bristol Castle )

The army also includes a Scot, an Irishman, an Englishman and Fluellen, a comically stereotyped Welsh soldier, whose name is an attempt at a phonetic rendition of " Llywelyn ".

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 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.

The construction of this castle between 1268 and 1271 by Gilbert de Clare, 6th Earl of Hertford | Gilbert de Clare led to a dispute between Llywelyn the Last and the English crown, one of the issues which led to the wars of 1277 and 1282 and the end of Welsh independence

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

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.

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.