The Welsh documents cover about the same period as the Irish and the Scottish. Four of these stand out from the rest, as most important. The oldest is the Black Book of Caermarthen, which dates from the third quarter of the twelfth century; the Book of Aneurin, which was written late in the thirteenth; the Book of Taliesin, assigned to the fourteenth; and the Red Book of Hergest, compiled by various persons during that century and the one following it. The first three of these “Four Ancient Books of Wales” are small in size, and contain poems attributed to the great traditional bards of the sixth century, Myrddin, Taliesin, and Aneurin. The last—the Red Book of Hergest—is far larger. In it are to be found Welsh translations of the British Chronicles; the oft-mentioned Triads, verses celebrating famous traditionary persons or things; ancient poems attributed to Llywarch Hên; and, of priceless value to any study of our subject, the so-called Mabinogion, stories in which large portions of the old British mythology are worked up into romantic form. The whole bulk, therefore, of the native literature bearing upon the mythology of the British Islands may be attributed to a period which lasted from the beginning of the twelfth century to the end of the sixteenth. But even the commencement of this era will no doubt seem far too late a day to allow authenticity to matter which ought to have vastly preceded it. The date, however, merely marks the final redaction of the contents of the manuscripts into the form in which they now exist, without bearing at all upon the time of their authorship. Avowedly copies of ancient poems and tales from much older manuscripts, the present books no more fix the period of the original composition of their contents than the presence of a portion of the _Canterbury Tales_ in a modern anthology of English poetry would assign Chaucer to the present year of grace.