A piece of black basalt bearing inscriptions that provided the key to the deciphering of Egyptian hieroglyphs. It was found in Rosetta (Rashid) near Alexandria in Egypt in 1799 by a French soldier during Napoleon’s occupation of Egypt, and contained three inscriptions, in Greek, in Egyptian demotic, and in Egyptian hieroglyphics. Comparative study of the three texts, which date from 196 bc, was undertaken by Thomas Young and Jean-François Champollion, the latter finally unlocking the secrets of hieroglyphics in 1821–22. The stone is housed in the British Museum in London.