Editing Llywelyn ap Gruffudd (section)

== Supremacy in Wales ==
[[File:Wales after the Treaty of Montgomery 1267 Colorblind.svg|thumb|upright=1.1|alt=Coloured map depicting Wales (adjacent to the Kingdom of England, coloured dark orange) following the Treaty of Montgomery of 1267. Gwynedd, Llywelyn ap Gruffudd's principality, is green; the territories conquered by Llywelyn are purple; the territories of Llywelyn's vassals are blue; the lordships of the Marcher barons are shown as light orange; and the lordships of the King of England are shown in yellow.|Wales after the [[Treaty of Montgomery]] of 1267:
{{Leftlegend|#009E73|[[Gwynedd]], Llywelyn ap Gruffudd's principality}}
{{Leftlegend|#CC79A7|Territories conquered by Llywelyn ap Gruffudd}}
{{Leftlegend|#56B4E9|Territories of Llywelyn's vassals}}
{{Leftlegend|#E69F00|Lordships of the [[Marcher barons]]}}
{{Leftlegend|#F0E442|Lordships of the King of England}}
{{Leftlegend|#D55E00|Kingdom of England}}]]

Llywelyn's interests were now not solely excluded to Wales. In England, [[Simon de Montfort the Younger|Simon de Montfort]] (the Younger) defeated the king's supporters at the [[Battle of Lewes]] in 1264 ([[Second Barons' War]]), capturing the king and Lord Edward. Llywelyn began negotiations with de Montfort, and in 1265, offered him 25,000 marks in exchange for a permanent peace, 5,000 of which immediately and then 3,000 a year thereafter. The [[Treaty of Pipton]], 22 June 1265, established an alliance between Llywelyn and de Montfort, although [[Pope Clement IV]] warned Llywelyn against allying himself with the excommunicated Montfort. As well as the rule of the whole Principality, Llywelyn was offered the castles of Maud, [[Hawarden Castle (medieval)|Hawarden]], [[Ellesmere Castle|Ellesmere]] and [[Montgomery Castle|Montgomery]].<ref name=Pierce/><ref name=Tout17/> Thus, Llywelyn's right to rule the [[Principality of Wales]] as the hereditary Prince of Wales would be acknowledged. De Montfort was to die at the [[Battle of Evesham]] in 1265, a battle in which Llywelyn took no part.<ref name=Tout17/>{{sfn|Turvey|2010|pages=101–102}} 

After Simon de Montfort's death, Llywelyn launched a campaign in order to rapidly gain a bargaining position before King Henry had fully recovered. In 1265, he routed the combined armies of [[Hamo le Strange]] and [[Maurice FitzGerald, 3rd Lord of Offaly|Maurice FitzGerald]] in North Wales.<ref name=Tout17/> Llywelyn then moved on to [[Montgomery, Powys|Montgomery]], and routed [[Roger Mortimer, 1st Baron Mortimer|Roger Mortimer]]'s army. With these victories and the backing of the papal legate,{{sfn|Tout|1893|page=16}} [[Pope Adrian V|Ottobuono]], Llywelyn opened negotiations with the king and was eventually recognised as Prince of Wales by King Henry in the [[Treaty of Montgomery]] in 1267.<ref name=Pierce/><ref name=Tout18/> All of the Welsh princes submitted to Llywelyn II except for [[Maredudd ap Rhys Gryg]]. For this recognition he would have to pay the English crown 24,000 marks in installments, this agreement was confirmed by the papacy in Rome.<ref name=Tout18/> If he wished, Llywelyn could purchase the homage of the one outstanding native prince –  Maredudd ap Rhys of Deheubarth – for 5,000 marks. However, Llywelyn's territorial ambitions gradually made him unpopular with some minor Welsh leaders, particularly the princes of South Wales.

The Treaty of Montgomery marked the high point of Llywelyn's power. Problems began arising soon afterward, initially a dispute with [[Gilbert de Clare, 7th Earl of Gloucester|Gilbert de Clare]] concerning the allegiance of a Welsh nobleman holding lands in [[Glamorgan]].<ref name=Tout18/> Gilbert built [[Caerphilly Castle]] in response to this.<ref>{{cite web |url=https://cadw.gov.wales/visit/places-to-visit/caerphilly-castle |website=cadw.gov.wales |title=Caerphilly castle |access-date=27 November 2023}}</ref> King Henry sent a bishop to take possession of the castle while the dispute was resolved but when Gilbert regained the castle by trickery, the king was unable to do anything about it.

Following the death of King Henry in late 1272, with the new King [[Edward I of England]] away from the kingdom on a [[Lord Edward's crusade|crusade]],<ref name=Tout18/> the rule fell to three men. One of them, Roger Mortimer was one of Llywelyn's rivals in the marches. When [[Humphrey de Bohun, 3rd Earl of Hereford|Humphrey de Bohun]] tried to take back [[Brycheiniog]], which was granted to Llywelyn by the Treaty of Montgomery, Mortimer supported de Bohun.{{citation needed|date=November 2023}} Llywelyn was also finding it difficult to raise the annual sums required under the terms of this treaty and ceased making payments.<ref name=Tout17/>

In early 1274, there was a plot by Llywelyn's brother, Dafydd,{{sfn|Turvey|2010|page=103}} and [[Gruffydd ap Gwenwynwyn]] of [[Powys Wenwynwyn]] and his son, [[Owen de la Pole|Owain]], to kill Llywelyn.<ref name=DafIII/> Dafydd was with Llywelyn at the time, and it was arranged that Owain would come with armed men on 2 February to carry out the assassination; however, he was prevented by a snowstorm. Llywelyn did not discover the full details of the plot until Owain confessed to the [[Bishop of Bangor]]. He said that the intention had been to make Dafydd prince of Gwynedd and that Dafydd would reward Gruffydd with lands. Dafydd and Gruffydd fled to England where they were maintained by the king and carried out raids on Llywelyn's lands, increasing Llywelyn's resentment. When Edward called Llywelyn to Chester in 1275 to pay homage, Llywelyn refused to attend.

Llywelyn also made an enemy of King Edward by continuing to ally himself with the family of Simon de Montfort, even though their power was now greatly reduced. Llywelyn sought to marry [[Eleanor de Montfort]], born c. 1258, Simon de Montfort's daughter. They were married by proxy in 1275, but King Edward took exception to the marriage, in part because Eleanor was his first cousin: her mother was [[Eleanor of England, Countess of Leicester|Eleanor of England]], daughter of [[John, King of England|King John]] and princess of the [[House of Plantagenet]]. When Eleanor sailed from [[France]] to meet Llywelyn, Edward hired men to seize her ship and she was imprisoned at [[Windsor Castle]] until Llywelyn made certain concessions.<ref name=Pierce/><ref name=elan>{{cite DWB|id=s11-ELEA-WRL-1200|title=Eleanor De Montfort (c. 1258–1282), princess and diplomat}}</ref><ref>{{cite DNB|wstitle=John (1167?–1216)|volume=29|page=416}}</ref><ref name=Tout18/>