​ ROSETTA (see Egypt, vol. vii. p. 768). The celebrated Rosetta Stone, a basalt stele containing a decree of Ptolemy V. Epiphanes in hieroglyphics, demotic, and Greek, which supplied the key for the decipherment of the ancient monuments of Egypt, was found near Fort St Julien, 4 miles north of the town, in 1799, by Boussard, a French officer. It is now in the British Museum.