On the death of the last-named bishop, a Dominican, by name Symon, was appointed by Pope Clement VI. to rule the See of Derry. He had indeed already been nominated by brief, dated the 5th of the Ides of May, 1347, to the diocese of Clonmacnoise, but the aged and infirm bishop of that see, who was reported to have passed to a better life, was not yet deceased, and hence, on the vacancy of Derry, Bishop Symon was, by brief of 18th December, 1347, appointed successor of St. Eugene. From the first brief, which nominated him to Clonmacnoise, we learn that Friar Symon was Prior of the Dominican fathers of Roscommon, and was remarkable for his zeal, his literary proficiency, and his manifold virtues. The brief of his appointment to Derry adds the following particulars:
“Dudum ad audientiam apostolatus nostri relatione minus vera perlata, quod Ecclesia Cluanensis per obitum Venerabilis fratris nostri Henrici Episcopi Cluanensis qui in partibus illis decessisse dicebatur, vacabat: Nos credentes relationem hujusmodi veram esse, de te ordinis fratrum Praedicatorum professore eidem Ecclesiae duximus providendum, praeficiendo te illi in Episcopum et pastorem: et subsequenter per Ven. fratrem nostrum Talayrandum Episcopum Albanensem tibi apud sedem Apostolicam fecimus munus consecrationis impendi. Cum autem sicut postea vera relatio ad nos perduxit praefatus Henricus tempore provisionis hujus modi ageret, sicut agere dignoscitur, in humanis, tu nullius Ecclesiae Episcopus remansisti. Postmodum vero Ecclesia Darensi, per obitum bonae memoriae Mauricii Episcopi Darensis qui extra Romanam curiam diem clausit extremum, pastoris solatio destitute, Nos ... cupientes talem eidem Darensi Ecclesiae praeesse personam quae sciret, vellet et posset eam in suis manutenere juribus ac etiam adaugere, ipsamque praeservare a noxiis et adversis, post deliberationem quam super his cum fratribus nostris habuimus diligentem, demum ad te consideratis grandium virtutum meritis, quibus personam tuam Dominus insignivit, convertimus oculos nostræ mentis, etc. Datum Avinione XV. Kalend. Januarii Pontif. Nostri anno octavo”—(_Mon. Vatic._, pag. 292).
Bishop Symon seems to have held the see till the close of this century, and the next bishop that we find was John, Abbot of Moycoscain, or _de claro fonte_, who was appointed to Derry by brief of Pope Boniface IX. on 19th August, 1401. Of his immediate successors we know little more than the mere names. William Quaplod, a Carmelite and a distinguished patron of literary men, died in 1421. Donald for ten years then ruled the diocese, and resigned in 1431; his successor, John, died in 1456. A Cistercian monk, named Bartholomew O’Flanagan, next sat in the see for five years; and Nicholas Weston, a canon of Armagh, who was consecrated its bishop in 1466, held it till his death in 1484.