- Gruffydd Aled Williams
Guto'r Glyn (fl. c. 1435–c. 1493), poet, is probably identifiable with Guto ap Siancyn y Glyn, though scholarly opinion is divided on this matter. The Glyn of his name may have been Glynceiriog or Glyndyfrdwy in Denbighshire. According to the later poet Tudur Aled it was Guto of all Welsh poets who excelled in composing praise poems to noblemen: his work amply bears out this judgement, often boldly transcending poetic convention and delighting with its wit, vigour, and original imagery [see also Cywyddwyr (c. 1330–c. 1650)]. As a young man Guto saw service in France, probably in the retinue of Sir William ap Thomas of Raglan, and addressed spirited poems to fellow Welshmen Sir Richard Gethin and Matthew Gough. Guto was a faithful Yorkist who served in Edward IV's guard, hailing the king in a poem as 'the great bull descended from the Mortimers'. Among his more important patrons were the sons of Sir William ap Thomas, William Herbert, first earl of Pembroke, and Sir Richard Herbert. The brothers' execution after the battle of Banbury in 1469 moved Guto to compose a poignant and bitter elegy, blaming the tragedy on English treachery. As well as these leading figures Guto's patrons included numerous members of the minor gentry and ecclesiastics, and during a long poetic career he travelled extensively throughout Wales. He settled in Oswestry, becoming a burgess there, before retiring in old age to Valle Crucis Abbey, Llangollen, where he was succoured by his friend and patron Abbot Dafydd ab Ieuan ab Iorwerth. He died at the abbey and was buried there.
- Gwaith Guto'r Glyn, ed. J. L. Williams and I. Williams (1939)
- J. Ll. Williams, ‘Guto ap Siancyn, neu Guto'r Glyn’, Y Llenor, 10 (1931), 152–60
- S. Lewis, ‘Gyrfa filwrol Guto'r Glyn’, Ysgrifau Beirniadol, 9 (1976), 80–99
- J. E. C. Williams, ‘Guto'r Glyn’, A guide to Welsh literature, ed. A. O. H. Jarman and G. R. Hughes, 2: 1282–c.1550 (1979), 218–42
- E. Roberts, Y beirdd a'u Noddwyr ym Maelor (1977)