MO-NENNIUS (fl. 500), bishop of Whithorn, and teacher of many Irish saints, was of Irish birth, but lived at Whithorn, Wigtownshire (Whitaern, Alba or Candida Casa), where St. Ninian was bishop early in the fifth century. He was apparently a protege of that saint, and it is suggested that his name, which appears in many forms, was derived from Nennio, a variant of Ninian, combined with the Irish prefix Mo-, denoting affection. Mo-nennius was a coarb or successor of St. Ninian as bishop of Whithorn, probably before 497, when he visited the island of Nendrum, now Mahee, on Strangford Lough, and was described as a bishop (Tighernach Annals). At Whithorn was a celebrated school sometimes called Mo-nasterium Rosnatense, or by Irish writers Futerna, which has occasionally been awkwardly confused with St. David's Magnum Monasterium or 'Rosina Vallis ' in Wales. Of the establishment at Whithorn Mo-nennius, who is otherwise known as Mansennus or Mugint, appears to have been master or abbat. While the school was under his direction Colman, bishop of Dromore, sent thither Finian of Moville to complete his education. Saints Eugenius, Enna, and Tigernach also seem to have been Mo-nennius's pupils, as well as Rioc, Talmach, and a lady, Drusticc, daughter of a British king, Drustic. The lady Drusticc fell in love with her fellow-pupil Rioc, and begged Finian to assist her union with Rioc, promising in return to get all their teacher's books for him to copy. Finian made himself in some measure a party to her plot, and when it was discovered, Mo-nennius, or Mugint as he is called in connection with this story, determined to kill him. In the belief that Finian would be the first to visit the church, he gave orders that the first to arrive there should be slain. The blow Mugint destined for Finian was, however, received by himself. In the lives of Finian the story of the plot is told in an altered form. The cause of their hostility is here said to have been the superior popularity of Finian's lectures. Mo-nennius was author of a hymn modelled on the penitential psalms, which is extant under the title of the 'Hymn of Mugint.' It is in Irish prose, and parts of it are embodied in the Anglican church service.
Meignant, Maugantius, Meugan, Meugant (fl. 6th cent.), a Welsh saint or druid, ought probably to be distinguished from the foregoing. His father was Gwynd af Hen, the son of Emyr Llydaw, and his mother was Gwenonwy, daughter of Meirig, king of Morganwg, the son of Tewdrig. Meigant was president of the college of St. Illtyd [q. v.] at Llantwit, called also the White House. He seems subsequently to have removed to the establishment of St. Dubricius [q. v.], who died in 612. He is doubtless identical with Mancennus or Mancan, who is mentioned as the head of a monastery, and as having received a present from St. David's father to be kept for his unborn son. From that time Mancan's house was called the 'house of the deposit.'
[In Dr. Todd's Irish Hymns, fascic. i., is printed Mugint's hymn with the Scholiast's Preface (Dr. Todd considers it a document of great antiquity, not far removed from Mugint's own period). See also Colgan's Acta SS. Hibern. p. 438; Lanigan's Eccles. Hist. Ireland, i. 437; Dict. Christian Biog.; Rees's Welsh Saints, p. 219; Iolo MSS. printed for Welsh MSS. Soc., p. 132; Life of St. David in Capgrave's Nova Legenda, and in W. J. Rees's Cambro-British Saints.]