Sir John Wynn (1553-March 1, 1627), Welsh baronet, member of parliament and antiquary, was the son of Morris Wynn and directly descended from the princes of Gwynedd through Rhodri ab Owain son of Owain Gwynedd. He was educated at Oxford, succeeded to his father's estate of Gwydir in Carnarvonshire in 1580, and was member of parliament for this county in 1586. In 1606 he was made a knight and in 1611 became the first of the Wynn Baronets. He was interested in several mining ventures and also found time for antiquarian studies. His son was Sir Richard Wynn.

At Llanrwst Wynn founded an hospital and endowed a school. His work The History of the Gwydir Family, which had a great reputation in North Wales, was intended to assert his claim to royal ancestry. In a legal challenge to these claim Thomas Prys of Plas Iolyn brought a case against him and Sir John was forced to defend himself in court. He won the case and afterwards was recognised as the senior male heir of the House of Gwynedd and under Welsh Law de jure Prince of Gwynedd. His book was first published by Dames Barrington in 1770, and in 1878 an edition was published at Oswestry. It is valuable as the only work which describes the state of society in North Wales in the 15th and the earlier part of the 16th century.

Male Line Descent of Sir John Wynn of Gwydir from Owain Gwynedd

• Owain Gwynedd, Prince of Gwynedd (d. November 1170) = Cristina ferch Gronw ap Owain ap Edwin
• Rhodri ab Owain Gwynedd, Lord of Anglesey (d.1195) = Annest ferch Rhys ap Gruffudd
• Tomas ap Rhodri = Annest ferch Einion ap Seisyllt
• Caradog ap Tomas = Efa ferch Gwyn ap Gruffudd ap Beli
• Gruffudd ap Caradog = Lleuca ferch Llywarch Fychan ap Llywarch
• Dafydd ap Gruffudd of Rhos = Efa ferch Gruffudd Fychan
• Hywel ap Dafydd = Efa ferch Evan ap Hywel ap Maredudd
• Maredudd ap Hywell (d. after 1353) = Morfydd verch Ieuan ap Dafydd ap Trahaern Goch
• Robert ap Maredudd = Angharad ferch Dafydd ap Llywelyn
• Ifan ap Robert (b. 1438, d. 1469) = Catherine ferch Rhys ap Hywel Fychan
• Maredudd ap Ifan (Ieuan) ap Robert (b. c1459, d. 18 March 1525) = Ales ferch William Gruffudd ap Robin
• John "Wynn" ap Maredudd (d. 9 July 1559) = Ellen Lloyd ferch Morys ap John
• Morys (Morris) Wynn ap John (d.1580) = Katherine Berain (1) Jane Bulkeley (2)
• Sir John Wynn ap Morys of Gwydir

Sir John Wynn's estate of Gwydir came to Robert Bertie, first Duke of Ancaster, in the 17th century, by his marriage with the heiress of the Wynns. On the death of the last duke in 1779, Gwydir was inherited by his sister Priscilla, Baronness Willoughby de Eresby in her own right, whose husband was created Baron Gwydir.

On the death of Alberic, Baron Willoughby de Eresby in 1870, this title (now merged in that of earl of Ancaster) fell into abeyance between his two daughters, while that of Baron Gwydir passed to his cousin and male heir. Gwydir itself was sold by the earl of Ancaster in 1895, the house and part of the estate being bought by Earl Carrington, who also claimed descent from Sir John Wynn.

 This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). Encyclopædia Britannica (11th ed.). Cambridge University Press. ((cite encyclopedia)): Missing or empty |title= (help)

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