This tumbler commemorates a union between members of the Richardson and Williamson families, presumably the Richardsons of Pencaitland and Smeaton near Perth in Scotland—possibly descendants of Sir Robert Richardson, who was the seventh baronet of Pencaitland (he died in Perth in 1752)—and the Williamsons of Cumberland in northwestern England. Alternatively, the glass may have been made for members of those families who lived in Durham, England. The object was enameled by William and Mary Beilby, members of a family of draftsmen who had founded a glass decorating workshop in the center of Newcastle in 1760. William (1740–1819) and his sister Mary (1749–1797), whom he taught to paint and enamel, as well as their brothers Ralph (1743–1817), an engraver and silversmith, and Thomas (1747–1826), a draftsman and enamel painter, are famed for their exceptional production of enameled glasses between 1761 and 1778. Their success followed the technical advances that William made in developing pigments with a flux that enabled him to fire enamel paints onto the surface of glass. The Beilbys are particularly noted for the armorial glasses they created from 1762 to 1769. For additional information on the Beilbys, see Simon Cottle, “William Beilby and the Art of Glass,” Glass Circle News, no. 74, February 1998, pp. 5–6; Frieder Ryser, Reverse Paintings on Glass: The Ryser Collection, ed. and trans. Rudy Eswarin, Corning: The Corning Museum of Glass, 1992; James Rush, A Beilby Odyssey, Olney, Bucks., U.K.: Nelson & Saunders, 1987; and James Rush, The Ingenious Beilbys, London: Barrie and Jenkins, 1973.