Sir John Wynn, 1st Baronet

[12] Wynn's work The History of the Gwydir Family, which had a great reputation in North Wales,[5] was intended to assert his claim to royal ancestry.

In a legal challenge to this claim, Thomas Prys of Plas Iolyn brought a case against him and Sir John was forced to defend himself in court.

Under Welsh succession law the head of the Price of Esgairweddan family at the time, descended through Iorwerth ab Owain Gwynedd and Dafydd II, would lead the senior line and be de jure Princes of Gwynedd, however they died out in the male line in 1702 and the royal title and headship of the House of Aberffraw would have passed then from the Price family to the Wynn Family of Gwydir at that time under the native succession law of Kings laid out in Cyfraith Hywel as descendants of one of the surviving senior lineages of the Welsh Royal Houses.

Gwydir itself was sold by the earl of Ancaster in 1895, the house and part of the estate being bought by Lord Carrington, who also claimed descent from Sir John Wynn.

[5] On 28 May 2010, Llanrwst celebrated the 400th anniversary of the almshouses there, which were built by Sir John Wynn to provide shelter for twelve poor older men of the parish.

[14] In this festival, Sir John Wynn was played by actor Sion Rickard, a student studying Performing Arts at Coleg Llandrillo, who arrived with his "wife" in the main square of Llanrwst by horse and carriage from Gwydir Castle, then answered questions from the local town crier, went inside the almshouse to check the standard of what he had built and delivered a speech to the people of Llanrwst.