Rosetta (rōzĕtˈə) [key], former name of Rashid räshēdˈ, city (1986 pop. 51,789), N Egypt, in the Nile River delta. The city once dominated the region's rice market; rice milling and fish processing are the main industries of modern Rashid. Founded in the 9th cent., the city was formerly an important port but declined after the building (1819) of the Mahmudiyah Canal, which diverted its trade to Alexandria.
The Rosetta Stone is a granitoid slab inscribed in hieroglyphic, demotic, and Greek with identical texts of a decree by a council of priests during the reign of Ptolemy V. Part of a stele dating from 196 B.C., it was found (1799) by Napoleon's troops near the city, was taken (1801) by the British, and since 1802 has been displayed at the British Museum. It gave Jean-François Champollion, Thomas Young, and others the key to Egyptian hieroglyphic.
See study by R. B. Parkinson (1999).