Siôn Dafydd Rhys

Dafydd Rhys came to Anglesey as gardener to Sir William Gruffydd of Penrhyn, who married Jane Stradling of St Donats, Glamorganshire.

Siôn's parents died when he was young, and he was brought up at St Donats and educated with the Stradlings.

[2] Following a two-day public examination, "Ioanes Dauit filius Domini Resi de Ciuitate Pangorio Anglus" was awarded the degree of Master of Arts and Doctor of Medicine in the great hall of the Archbishop of Siena by the Vicar, his deputy, on 2 July 1567.

[4] Rhys returned to north Wales in the early 1570s and became headmaster of the Friars' Grammar School in Bangor.

In 1577 he was invited by Bishop Richard Davies of St David's to join him at the episcopal palace near Carmarthen.

[1][a] Wood asserts that Rhys died a Roman Catholic, but Prichard calls him "sinceræ religionis propagandæ avidissimus."

The discussion of Welsh prosody is long and tedious, and copies entire passages from the bardic treatises.

[3] Rhys also wrote a long treatise on the early history of Britain in which he defends the historical value of Geoffrey of Monmouth's Historia Regum Britanniae against the attacks by Polydore Vergil and others.

[2] A manuscript translation into Welsh by Rhys of Aristotle's Metaphysics is said to have once existed in the library of Jesus College, Oxford.

[3] The National Library of Wales has a manuscript translation into Welsh by Rhys of a Latin poem by Thomas Leyson in praise of St Donat's.