Robert Vaughan of Hengwrt is most esteemed not as an author (only one of his projected writings reached publication) nor as a scholar and antiquary--though, as such, he was among the most scrupulous and acute of his age--but, rather, as the collector of the most important library of Welsh manuscripts ever brought together by one person. In contrast to other seventeenth-century Welsh collections, his collection has, in large part, survived intact. By 1667 more than half of the medieval manuscripts in Welsh that survive today had been gathered in his study at Hengwrt, and of the surviving manuscripts that are generally regarded as preeminent in importance to Welsh literature or history, the collection contained about two-thirds. In effect, much as Sir Robert Cotton had done for England at Cotton House, Westminster, a decade or two earlier, Vaughan had created a national collection for Wales. Vaughan wrote of his antiquarian...