The Rosetta Stone, 196 BC; a fragment of a larger basalt steele, was written in Egyptian hieroglyph, Demotic (a shorthand) and Greek. Found by Napoleon's French soldiers while building a fort, it is now in the British Museum, London.
The Rosetta Stone has the same inscription written in three languages; Ancient Egyptian hieroglyphs, Demotic, and Greek. Its discovery in 1799 was key to figuring out the hieroglyphic writing system, thus allowing modern historians to unlock the contents of many manuscripts and carvings that were previously unknown. The Rosetta Stone is currently located in the British Museum.