From A Compendium of Irish Biography, 1878
Dungal, a writer of the 9th century, an Irishman, who settled in France, probably on account of the Danish invasions of Ireland. He became eminent as a teacher, and his latter days were devoted to cultivating philosophy and astronomy. His reputation in the latter science became so great that in 811 he was consulted by Charlemagne concerning an eclipse which had taken place the year before. In 827 he wrote a treatise in defence of images, against Claude, Bishop of Turin, printed in 1608. Some of his poetical pieces are stated to have been printed in a collection of poems published in France in 1729. The date of his death is not known.
42. Biographical Dictionary: Rev. Hugh J. Rose. 12 vols. London, 1850.
339. Ware, Sir James, Works: Walter Harris. 2 vols. Dublin, 1764.