GEOFFREY OF MONMOUTH (d. I154), bishop of St. Asaph and creator of the Arthurian legend, was born about the year I I oo. He received a liberal education under his paternal uncle, Uchtryd, at that time archdeacon, and subsequently bishop, of Llandaff. In 1129 Geoffrey appears at Oxford among the wit nesses of an Oseney charter. He subscribes himself "Geoffrey Arturus." A first edition of his Historia Britonum was in circu lation by the year 1139, although the text which we possess ap pears to date from 1147. This famous work professes to be a translation from a Celtic source; "a very old book in the British tongue" which Walter, archdeacon of Oxford, had brought from Brittany. Walter the archdeacon is a historical personage; whether his book has any real existence may be fairly questioned. There is nothing in the matter or the style of the Historia to preclude us from supposing that Geoffrey drew partly upon con fused traditions, partly on his own powers of invention, and to a very slight degree upon the accepted authorities for early British history. The romancer achieved an immediate success. He was patronized by Robert, earl of Gloucester, and by two bishops of Lincoln; he obtained, about 1140, the archdeaconry of Llandaff "on account of his learning"; and in 1151 was promoted to the see of St. Asaph.
Before his death the Historia Britonum had already become a model and a quarry for poets and chroniclers. The list of imi tators begins with Geoffrey Gaimar, the author of the Estorie des Engles (c. I 147), and Wace, whose Roman de Brut (1 I S 5) is partly a translation and partly a free paraphrase of the Historia. In the next century the influence of Geoffrey appears in the Brut of Layamon, and in the rhyming English chronicle of Robert of Gloucester. Among later historians who were deceived by the Historia Britonum it is only needful to mention Higden, Hardyng, Fabyan 0512), Holinshed (158o) and John Milton. Still greater was the influence of Geoffrey upon Warner in Albion's England (1586), and Drayton in Polyolbion (1613). The Historia Bri tonum provided the material for the earliest English tragedy, Gorboduc 0565), the Mirror for Magistrates (1587), and Shake speare's Lear.
But in the work of expanding and elaborating this theme the successors of Geoffrey went as far beyond him as he had gone beyond Nennius; but he retains the credit due to the founder of a great school. For the development of the tradition see ARTHU RIAN LEGEND. Of the twelve books into which it is divided only three (Bks. IX., X., XI.) are concerned with Arthur. Earlier in the work, however, we have the adventures of Brutus; of his fol lower Corineus, the vanquisher of the Cornish giant Goemagol (Gogmagog) ; of Locrinus and his daughter Sabre (immortalized in Milton's Comics); of Bladud the builder of Bath; of Lear and his daughters; of the three pairs of brothers, Ferrex and Porrex, Brennius and Belinus, Elidure and Peridure. The story of Vor tigern and Rowena takes its final form in the Historia Britonum; and Merlin makes his first appearance in the prelude to the Arthur legend. Besides the Historia Britonum Geoffrey is also credited with a Life of Merlin composed in Latin verse. The authorship of this work has, however, been disputed, on the ground that the style is distinctly superior to that of the Historia. A minor com position, the Prophecies of Merlin, was written before 1136, and afterwards incorporated with the Historia, of which it forms the seventh book.