Dictionary of National Biography, 1885-1900/Sion Lleyn
SION LLEYN, known to his neighbours as John Roberts (1749–1817), Welsh poet, was born in 1749 at Traean in the parish of Llan Armon, Carnarvonshire. He spent most of his life as a schoolmaster at Pwllheli, in the Lleyn district of the same county. Becoming skilful in the Welsh ‘strict’ metres, he was for about forty years a well-known, though not specially gifted, member of the group of the Carnarvonshire poets who held a commanding position at this time. Dafydd Ddu Eryri was his close friend and correspondent, and in 1810 included in his collection of Welsh verse entitled ‘Corph y Gainc’ four of the compositions of Sion Lleyn. In 1800 Roberts wrote for the Gwyneddigion Society of London a ‘cywydd’ on ‘Knowledge and Learning,’ which the society printed soon after with some other poems. Ashton mentions (Hanes Llenyddiaeth Gymreig, p. 590) a pamphlet printed at Dolgelly (no date) entitled ‘Caniadau Moesawl a Difyr,’ as the work of Sion Lleyn; but most of his poems are, it is believed, still in manuscript. He died 7 May 1817, and was buried at Deneio, near Pwllheli. Sion Wyn o Eifion (John Thomas) was his nephew. ‘Gardd Eifion’ (Dolgelly, 1841) contains (pp. 111–12) an elegy by Robert ap Gwilym Ddu upon him.
[Ashton's Hanes Llenyddiaeth Gymreig; letters in Adgof uwch Anghof (Penygroes, 1883); Leathart's History of the Gwyneddigion, p. 33.]