The Rosetta Stone is the icon of decipherment. As one of the most popular objects in the British Museum, its irregular shape and the once white-on-black of its three scripts — hieroglyphic, demotic, Greek — are distinctive enough to sell countless socks, keyrings and nail files in the museum shop. The stone’s marketable popularity testifies both to the allure of hieroglyphs, including a persistent orientalising idea of their ‘mystery’, and the seemingly miraculous achievement of code-breaking. The latter is most associated with the two men of The Riddle of the Rosetta’s subtitle: the ‘English polymath’ Thomas Young (1773-1829) and the ‘French polyglot’ Jean-François Champollion (1790-1832). Theirs is a story much told and much mythologised.