The Rosetta Stone is considered an archaeological treasure and an invaluable historical artifact because it provided the ultimate key to deciphering Egyptian hieroglyphs. Before its discovery in 1799, the ancient script had remained a complete mystery for over a millennium, leaving scholars unable to read the vast textual heritage of ancient Egypt. The artifact is a granodiorite stele inscribed with a single administrative decree issued in Memphis in 196 BC, but crucially, it is written in three distinct scripts: Ancient Egyptian hieroglyphs, Demotic script, and Ancient Greek. Because linguists and historians were already capable of reading Ancient Greek, they were able to use it as a comparative bridge to cross-reference matching passages and unlock the phonetic and symbolic meanings of the mysterious hieroglyphic characters.