Editing Llywelyn ab Iorwerth (section)

=== Marital problems 1230 ===
Following his capture, William de Braose decided to ally himself to Llywelyn, and a marriage was arranged between his daughter Isabella and Llywelyn's heir, Dafydd ap Llywelyn. At Easter 1230, William visited Llywelyn's court. During this visit, he was found in Llywelyn's chamber together with Llywelyn's wife Joan. On 2 May, de Braose was hanged; Joan was placed under house arrest for a year. The ''[[Brut y Tywysogion]]'' chronicler commented: 
:"That year William de Braose the Younger, Lord of Abergavenny, was hanged by the lord Llywelyn in Gwynedd after he had been caught in Llywelyn's chamber with the king of England's daughter, Llywelyn's wife."{{sfn|Williams|1860|pp=190–191}}

A letter from Llywelyn to William's wife, [[Eva Marshal]], written shortly after the execution enquires whether she still wishes the marriage between Dafydd and Isabella to take place.{{sfn|Pryce|2005|pp=428–429}} The marriage did go ahead, and the following year Joan was forgiven and restored to her position as princess.

Until 1230, Llywelyn had used the title ''princeps Norwalliæ'' "Prince of North Wales", but from that year he changed his title to "Prince of Aberffraw and Lord of Snowdon".<ref name=DWB/>{{#tag:ref|The version of the Welsh laws preserved in ''Llyfr Iorwerth'', compiled in Gwynedd during Llywelyn's reign, claims precedence for the ruler of Aberffraw, the ancient court, over the rulers of the other Welsh kingdoms. See Aled Rhys William (1960) ''Llyfr Iorwerth: a critical text of the Venedotian code of mediaeval Welsh law''|group=ll}} He was, however, more concerned with the reality of power rather than its appearance. He never claimed or used the title "Prince of Wales" despite his authority extending over other rulers in Wales.{{sfn|Carpenter|2020|pp=232–233}}