For more years than I care to contemplate, when they appeared in the catalogues of antiquarian booksellers, and when I could more or less afford them, I have bought books which make a notable contribution to knowledge of the history of Wales. That they do not turn up often is an indication of their relative rarity, and a blessing of sorts: more would be a temptation to imprudence and financial ruin. Some time ago I acquired De calamitate excidio, & conquestu Britannie (Concerning the calamity of the ruin and conquest of Britain), the earliest surviving account of Britain in the fifth century, written about the middle of the sixth century by the monk Gildas. The text exists in manuscripts from the eleventh century, and the first printed version was published in April 1525 by Polydore Vergil (c.1470–1555), scholar priest of Urbino, who, despatched to England in 1502 as a collector of Peter’s Pence, found there ecclesiastical preferment and a niche at the court of Henry VII. In about 1505 he began writing Anglica Historia, probably at the king’s commission. The quest for materials to assist this project led him to investigate various manuscript sources, among them the Gildas, which is referred to in his history of England, the first edition of which was published in 1534. Detractors later claimed he destroyed manuscripts after filleting them, but the care he took to edit and publish De excidio gives the lie to that accusation. The copy I have once belonged to William Constable, Esq., FRS & FSA (1721–91), of Burton Constable Hall, a magnificent Elizabethan house ...