The conventional story of the fate of James II's Great Seal, that he cast it into the Thames in the course of his flight from Whitehall in the early hours of 11th December 1688, was challenged by the late Sir Hilary Jenkinson in an enthralling article in the Antiquaries Journal in 1943. He perceived that in design and size the counterseal used by William and Mary for their Great Seal (1689) is wellnigh identical with that used by James II, except that a figure of Mary mounted on horseback has been crudely intruded into it; the inscription is new. With this in mind he examined the statements of a number of contemporary writers and later historians about what happened to James's Great Seal and, finding a number of discrepancies among them, argued that the conventional story is extremely doubtful, if not false, and that William and Mary made use of James's counterseal—the actual matrix—with comparatively slight alterations. In a final section he noted the resemblance between impressions of both seal and counterseal of James II and those of William III's seal and counterseal (1695), and suggested, with only a slight reservation (‘I am afraid we cannot say with absolute certainty that the actual matrices engraved by John Roettier in 1685 were still in existence in 1702’), that William was now using both of James's matrices. The suggestion appears as a statement of fact, with no reservation, in Sir Hilary's Guide to the Seals in the Public Record Office, 1954.