Open almost any glossy magazine — especially if it’s sponsored by an airline — and you’re likely to find an advertisement for Rosetta Stone, a computer-assisted program for learning a foreign language. Roughly 200 years ago, however, the original Rosetta Stone provided the key to deciphering the most beautiful and enigmatic of all writing systems, ancient Egyptian hieroglyphics. The man who finally cracked the code was a young Frenchman named Jean-Francois Champollion (1790-1832).

But first some background.

Since the time of Herodotus, Europeans had been fascinated by hieroglyphs, those little pictographs of birds, geometrical figures, snakes, crouching lions, shepherd’s crooks and striding figures so familiar to us from such movies as “The Mummy.” This mysterious writing appeared on sarcophagi and the walls of royal tombs, on clay shards, obelisks and bits of papyrus. But what did the individual symbols mean?

The last known use of hieroglyphs occurred in A.D. 394, but the writing system had already grown esoteric, used principally by a priestly caste and pretty much a mystery to everyone else. As a result, hieroglyphs came to be regarded as emblematic or allegorical, each figure a concentrate of complex meaning, like a cross or the diagram of a fish among Christians. While learned scholars guessed at the significance of the various squiggles and symbols, no one could actually read the writing.

All that began to change in 1798when Napoleon’s armies invaded Egypt. The emperor brought not just a military force but also a small corps of savants and scientists, who eventually produced a nine-volume “Description of Egypt.” So when, in July 1799, near Rashid — known as Rosetta to Europeans — a squad of engineers unearthed a slab containing three parallel inscriptions, it was sent right off to headquarters in Cairo. The importance of the find was immediately recognized and copies of the inscriptions made. Eventually, though, the French lost the Rosetta Stone to the victorious English, and it now resides as the jewel of the Egyptian halls of the British Museum.

The Rosetta Stone contains essentially the same information — a court decree — in three scripts: hieroglyphics, a kind of Egyptian cursive now called Demotic, and ancient Greek. Early would-be decipherers quickly realized that recognizable names in the Greek section must appear in the other sections, as well. The Demotic lettering, it was determined, spelled out its words as did the Greek. The hieroglyphs apparently didn’t conform to this pattern. But, then, everyone knew they were symbolic, not phonetic.

Except, as it turned out, they could be both, as Champollion gradually came to recognize.

Champollion was born in Figeac, the son of a bookseller. His 12-years-older brother, Jacques-Joseph, went on to become a noted paleographer and librarian and eventually curator of manuscripts at the National Library in Paris. The two were close and Champollion-Figeac — as Jacques-Joseph came to be known — fostered and supported his more brilliant sibling’s career.