In 1799 Napoleon's army uncovered an ancient stele in the Nile delta. Its inscription, recorded in three distinct scripts--ancient Greek, Coptic, and hieroglyphic--would provide scholars with the first clues to unlocking the secrets of Egyptian hieroglyphs, a language lost for nearly two millennia. More than twenty years later a remarkably gifted Frenchman named Jean-Francois Champollion successfully deciphered the hieroglyphs on the stele, now commonly...