Dictionary of National Biography, 1885-1900/Sulien
SULIEN, SULGEN (the old Welsh form), or SULGENUS (1011–1091), bishop of St. David's, was born of a good (perhaps clerical) family settled at Llanbadarn Fawr in Cardiganshire in 1011. He studied in monastic schools in Wales, Ireland (where he spent thirteen years), and Scotland, and then returned, with a great store of learning, to his native district, where he soon made a reputation as a teacher. The four sons born to him during this period, Rhygyfarch [q. v.], Arthen, Daniel, and Ieuan, became (with the exception, possibly, of Arthen) clerics like himself, and scholars of the same type. In 1073 on the death of Bleiddud, Sulien was chosen bishop of St. David's, but in 1078 he resigned the office and betook himself again to his studies. On the death of his successor, Abraham, in 1080, he was persuaded to become bishop once again, and in that capacity no doubt received William I when that monarch visited St. David's in 1081. In 1086 he resigned a second time. He died on 1 Jan. 1091. ‘Brut y Tywysogion’ styles him ‘the wisest of Welshmen,’ and refers to his circle of disciples. There is some manuscript evidence of the literary activity fostered by his school. It was at his request that his son Ieuan wrote, about 1090, the transcript of Augustine's ‘De Trinitate,’ extant in Corpus Christi College, Cambridge MS. 199. Of the sons, Daniel became archdeacon of Powys (d. 1127), and Ieuan archpresbyter of Llanbadarn (d. 1137); Arthen left a son Henry (d. 1163), who was celebrated as a scholar.
[Annales Cambriæ; Brut y Tywysogion and Brut y Saeson; Poem of Ieuan's printed by Haddan and Stubbs, Councils, i. 663–7; Archæologia Cambrensis, I. i. (1846), 117–25.]