GILDAS (516?–570?), British historian, tells us that he was born in the year of the battle of Mount Badon (Mons Badonicus), but gives no indication of the date of the battle. The tenth-century Latin chronicle, which is our next best authority after him for early Welsh history, puts this battle seventy-two years after the point at which its own record begins (Harl. MS. 3859, generally quoted as ‘Annales Cambriæ MS. A’). The editors of the ‘Monumenta Historica Britannica’ make the chronicle begin in 444, which would give 516 for the date of both the battle and Gildas's birth. Apparently following or inspiring ‘Nennius,’ the chronicle treats the battle of Mons Badonicus as the special victory of Arthur, while Gildas makes no mention whatever of Arthur; but he is so vague that it is unsafe to argue too much from his omissions. M. Arthur de la Borderie has recently maintained that the true date of Gildas's birth is fixed by a passage in Bæda (Hist. Ecclesiastica, bk. i. ch. xvi.), which dates the battle in the forty-fourth year after the arrival of the English in Britain, that is in 493. Advocates of the later date have supposed that Bæda, who is copying Gildas at this point, has misunderstood his author; but M. de la Borderie maintains that this and many other difficulties are avoided by adopting the earlier date. That date is also consistent with the statement of the monk of Ruys and the ninth-century author of the life of St. Paul Aurelian, that Gildas was a disciple of St. Illtyd, and a friend of St. Brigitta. But the materials hardly permit of a satisfactory solution (see Revue Celtique, vi. 1–13, ‘La date de la naissance de Gildas,’ par Arthur de la Borderie). If we follow Ussher and Mr. Stevenson (Preface to Gildas, p. ix), we put the date of Gildas's birth in 520. We can also gather from Gildas that he was an ecclesiastic, doubtless a monk. The whole tone of his work shows him a man of gloomy temper, irritated and saddened by the triumphs of the Saxons, and profoundly conscious of the vices and weaknesses of his countrymen. He enumerates the chief British kings who were his contemporaries, and expatiates in turgid and vague rhetoric upon their wicked characters. They are Constantinus, ‘the tyrant of Damnonia,’ Aurelius Conanus (Cynan), Vortiporius, ‘tyrant of the Demetians’ (South Welsh), Cuneglasus (Cyneglas), and the ‘island dragon’ Maglocunus (Maelgwn). The tenth-century chronicle places the death of Maelgwn in 547, and the ‘conversion of Constantine to the Lord’ in 589.
Gildas also tells us that he crossed the sea; that though strongly pressed by his friends to write his book, he refrained from doing so from want of information, and when after ten years' hesitation he undertook the task, he had still to trust to foreign accounts, ‘broken by repeated chasms and not sufficiently clear.’ He also says that at the time of his writing forty-three years and one month had elapsed from the siege of Mons Badonicus and the year of his own birth. It may be inferred from the above statements, and the known connections between Britain and Armorica, that Gildas wrote his work in Brittany, and that he crossed over thither not later than 550. This agrees with the positive statement of Gildas's eleventh-century Breton biographer, who says that he went to Gaul when in his thirtieth year. He is reputed to have founded there the monastery of St. Gildas at Ruys, on the peninsula that protects Vannes from the sea. This is very likely to be the case. His biographer was a monk of Ruys, who wrote to exalt the fame of his founder. The abbey itself became very famous as the place of the retirement of Abelard. The tenth-century annals of Wales seem to place Gildas's death in 570. He was regarded as a saint, and his day was kept on 29 Jan. Writing at the end of the ninth century, Alcuin in his epistles twice refers to Gildas's book, and calls him the wisest of the Britons (Jaffé, ‘Monumenta Alcuiniana,’ in Bibl. Rer. Germ. vi. 206, 371). Alcuin spells his name ‘Gildus.’ The twelfth-century manuscript of Gildas's history styles him in its rubrics ‘Saint Gildas the Wise.’ Gildas's statements gained wide currency from the use of his book by Bæda in the introductory chapters of his ‘Ecclesiastical History.’ Bæda speaks of him in one place as ‘Gildus, the historian of the Britons’ (Hist. Eccl. lib. i. chap. xxii.). Gildas remained a popular saint in Brittany, where in 1026 another monastery, that of St. Gildas du Bois (about midway between Vannes and Nantes), was founded in his honour (Sainte-Marthe, Gallia Christiana, xiv. 847). About 1830 a popular metrical hymn on his merits was published at Vannes in Breton (Cannen Spirituel. Buhé Sant Gueltas).
A much more detailed account of Gildas's life is to be found in the pages of the monk of Ruys. But apart from its late date and plainly legendary character, its statements harmonise so little with chronology that they can be safely disregarded. A second life of Gildas is also extant, which seems to have been the result of the renewed intercourse between Brittany and Wales in the twelfth century. It is ascribed to Caradog of Llancarvan [q. v.], the friend and fellow-worker of Geoffrey of Monmouth and William of Malmesbury. Though Caradog's authorship is denied by the editor of the life, it does not seem to be altogether unlikely. It is equally untrustworthy with the Breton life, from which, however, it differs in some important points. For instance, Caradog makes Gildas be buried at Glastonbury, while the monk of Ruys of course buries him at Ruys. Those who have given any credence to either have been compelled to start the hypothesis that there were two persons of the name of Gildas, one of whom, flourishing in the fifth century, they call ‘Gildas Albanius,’ while the author of the British history they call ‘Gildas Badonicus.’ But this is mere guesswork, and leaves so many difficulties that other writers have assumed the existence of three, if not four, historical Gildases.
Gildas's historical work is called in the rubric of the oldest extant manuscript, ‘Liber querulus de excidio Britanniæ.’ It is divided in the editions into a first part called ‘Historia Gildæ,’ and a second part ‘Epistola Gildæ;’ but it is plainly a continuous work, and the division seems due to early transcribers. The literary merit of the work is very small, and its historical value depends mainly upon the absence of better authorities. The style is extraordinarily verbose, rhetorical, involved, and obscure, while very few definite facts can be extricated. Bæda describes it as a ‘sermo flebilis.’ It was believed by William of Malmesbury, Henry of Huntingdon, Geoffrey of Monmouth, and Giraldus Cambrensis, that the curious compilation now generally assigned to Nennius [q. v.] was the work of Gildas, but that is plainly impossible. Pits and Bale attribute a long list of works to Gildas, but they have no good authority for doing so.
Gildas's history was first printed at London by Polydore Vergil in 1525, and has been many times reprinted. In 1568 John Joscelyn, Archbishop Parker's secretary, published a new edition. In 1691 it was again printed by Gale in the third volume of his ‘Rerum Anglicarum Scriptores.’ The best editions are that of Mr. Stevenson (English Historical Society, 1838), reprinted in 1844 by Sainte-Marthe (Schulz) at Berlin, and that in the ‘Monumenta Historica Britannica’ (1848). ‘The Epistle of Gildas, faithfully translated out of the Original Latine, with introduction by J. Habington’ (London, 1638, 12mo), was the first version in English. Another English translation can be found in Bohn's ‘Six Old English Chronicles,’ pp. 295–380. There are only two manuscripts of Gildas extant, both in the Cambridge University Library.[Hardy's Preface to Monumenta Historica Britannica, pp. 59–62; Stevenson's Prefaces and Notes to the English Historical Society's edition of the Historia; Wright's Biographia Britannica Literaria, Anglo-Saxon period, pp. 115–35; Schöll, De Ecclesiasticæ Britonum Scotorumque Historiæ fontibus, cap. i.; Skene's Four Ancient Books of Wales, vol. i. cap. iii.; A. de la Borderie in Revue Celtique, vol. vi.; Brit. Mus. Cat. of Printed Books; Dictionary of Christian Biography; Bædæ Historia Ecclesiastica Gentis Anglorum; Annales Cambriæ MS. A., confused in Mon. Hist. Brit. and in Rolls Ser. edition with less authoritative sources, but recently carefully printed by itself from the tenth-century Harleian MS., by Mr. Phillimore in the Transactions of the Cymmrodorion Society, ix. 141–83. Walter, Das alte Wales, pp. 41–2, gives a list of several other sources, many of very little critical value. The Life of Gildas by the monk of St. Gildas de Ruys has been published completely by Mabillon in the Acta Sanctorum Ordinis S. Benedicti, i. 138–89, and less fully in the Bollandist Acta Sanctorum, January, tom. iii. 573 sq. The Life ascribed to Caradog was first published from the manuscript in Corpus Christi Coll. Cambridge, by Stevenson in the Engl. Hist. Soc. edition of Gildas; for other lives see Hardy's Descriptive Cat. of Materials, i. pt. i. 132–7, 151–6, pt. ii. 799.]