Llewelyn ap Iorwerth (Llewelyn the Great)
Following the death of Rhys ap Grufudd in 1197, his kingdom of Deheubarth was torn by squabbles between his sons for control. The eldest son, Grufudd, was nominally his father's heir, a situation that his brothers Maelgwn and Rhys Gryg, refused to accept. In their struggles for power they weakened the strongest of the Welsh kingdoms.
In 1199 Maelgwyn appealed to King John of England for support. John was in the interesting position of being a Marcher Lord himself, as well as king of England; he held the territory of Glamorgan through his wife.
John granted Maelgwn the territories of Ceredigion and Emlyn in exchange for the castle of Cardigan, one of the major strongholds in the south of Wales. In Powys the situation was equally fragmented. That once powerful kingdom was divided into two parts, Powys Wenwynwyn (roughly approximate with Montgomeryshire) and Powys Fadog (northern Powys).
The ruler of Powys Wenwynwyn was Gwenwynwyn, who tried unsuccessfully to deal with the acquisitive Marcher Lords of the south. Gwenwynwyn was soundly beaten at Paincastle in 1198, and his dream of leading a Welsh resurgence in the south was crushed.
In the north, however, a new leader was about to appear. In 1200 the 28 year old Llewelyn ap Iorwerth came to the throne of Gwynedd. Llewelyn swore an oath of allegiance to King John in 1201, and John sought to bind him to the English crown by marrying him to his illegitimate daughter Joan.
In 1208 Llewelyn moved against Ceredigion and Powys Wenwynwyn and forced Gwenwynwyn to swear allegiance. He was careful not to antagonise John, and even accompanied the English king on his campaign against the Scots in 1209. But John was not an easy man to remain on friendly terms with.
John became concerned that Llewelyn was gaining too much power in Wales, and in 1211 he invaded Gwynedd and forced his former ally to give up all his lands except Gwynedd Uwch Conwy. Llewelyn was compelled to name John his heir in case his marriage with Joan did not produce a son.
Many of the Welsh lords deserted Llewelyn and swore allegiance to John, preferring an overlord who lived far away. They thought John would leave them largely alone, but their choice was soon proved to be an unwise one. John began erecting a castle near Aberystwyth and showed his intention to exert direct control in Powys.
The Welsh fled back to Llewelyn, who burned John's castle and launched a series attacks upon the Marcher Lords. They had an unlikely ally in their fight against the English Crown; the Pope. John had managed to anger Pope Innocent III (John eventually angered nearly everyone) and the Pope responded by placing John and his kingdom under interdict, which essentially meant that all his realm - including Wales - were without the benefit of religious services.
Therefore, by attacking John, Llewelyn was acting in the best interests of the Pope, who gave the rebellion his blessing.
John was hampered by his struggle with his own barons. In 1213 he patched up his feud with Pope Innocent, but he managed to further alienate his own subjects by losing Normandy to the French. Llewelyn siezed on this opportunity to ally himself with some of John's most powerful enemies within England. In 1215 he marched into English territory and took the town of Shrewsbury.
John was forced to bow to the demands of his enemies and in that same year he signed the Magna Carta.
Llewelyn took advantage of the ensuing civil war in England between John and his nobles to sieze more territory within Wales. He captured Norman castles in the south and when Gwenwynwyn rebelled against him Llewelyn siezed Powys Wenwynwyn for his own. He forced Deheubarth and Powys Fadog to acknowledge his overlordship.
In a historic assembly held at Aberdyfi in 1216, the other Welsh rulers formally paid homage and swore allegiance to Llewelyn. In a few short years Llewelyn had made himself the de facto ruler of all Wales outside the lands of the Marcher Lords. This fact was recognised formally by the English crown in 1218 by the Treaty of Worcester.
The English mistrusted the power of Llewelyn, however, and on several occassions they sought to restrict his control in Wales. At the Battle of Ceri in 1228 Llewelyn defeated forces led by Hubert de Burgh, the justiciar of England.
Llewelyn was never one to shy away from a fight or wait for his enemy to move first. In 1231 he marched south through Glamorgan and wreaked havoc in the south.
His relationship with Henry III was one of ups and downs. Henry supported Llewelyn's efforts to have his wife Joan (Henry's half-sister) declared legitimate. He also supported Llewelyn's move to have his eldest son, Grufudd, disinheirited in favour of Dafyd, his son by Joan. At a special assembly in 1226, Dafyd was declared heir to Gwynedd and received oaths of allegiance from Llewelyn's vassals.
All was not enmity between Llewelyn and the Marcher Lords, either. All Llewelyn's children save Grufudd married into Norman Marcher families. Llewelyn's long-term friendship with Ranulf, Earl of Chester, meant that the eastern border of Gwynedd was blessedly safe from attack.
Llewelyn's daughter, Helen, even married Ranulf's nephew and heir, John. This, though, would prove to be a double-edged sword, as alliances between the Welsh and English often were. When John died without producing an heir, his lands passed to the crown of England. This simple fact later allowed Edward II to use Chester as an important staging place for his invasion and subjugation of Wales.
Llewelyn ap Iorwerth died in 1240 at Aberconwy Abbey.