Science history: Rosetta stone is deciphered, opening a window into ancient Egyptian civilization — Sept. 27, 1822

On Sept. 27, 1822, French philologist Jean-François Champollion announced that he had deciphered the text on the Rosetta stone, opening a window into ancient Egyptian civilization.

The stone had been discovered by French forces in 1799, during Napoleon's first foray into Egypt. The soldiers were building fortifications in the town of Rashid, which had been ancient Rosetta, when officer Pierre François Bouchard noticed the granite-like stone built into an old wall.

The 44-inch-tall (112 centimeters), 1,680-pound (760 kilograms) slab of granodiorite was inscribed in Greek, hieroglyphics and demotic, a kind of cursive Egyptian script. Bouchard immediately realized its significance and surmised that the text was identical in all three languages. That meant the ancient Greek could potentially be used to decrypt the other two scripts, which had been indecipherable for centuries.

Ottoman and British forces defeated the French, and in 1801, the Rosetta stone was taken by the British as part of the Treaty of Alexandria and moved to the British Museum.

Based on the Greek inscription, scholars quickly deduced that the text was a royal decree from 196 B.C. that was written in honor of boy king Ptolemy V Epiphanes on the first anniversary of his coronation. The aim of the decree was to assert the Macedonian Greek pharaoh's authority at a tumultuous time, soon after rebellion by the native Egyptians had roiled the Hellenistic hierarchy and the nearby Seleucid Empire had invaded parts of the western Mediterranean.

The inscribed stone slab, or stela, pronounces that Ptolemy, "the god who maketh himself manifest," will fund temples and animal cults, increase priestly income, lighten the tax burden and pardon prisoners. In exchange, statues of him would be placed in all of the temples and priests would tend to those statues thrice daily. Similar stelae were placed throughout the country.

By 1802, a Swedish diplomat had made progress in deciphering some of the words in demotic by relying on its similarity with Coptic, an Egyptian language that, like Latin, wasn't spoken but was still understood.

But it wasn't until 1819 that the key breakthroughs were made. British scholar Thomas Young published an article in the Encyclopedia Britannica in which he defined 218 demotic words and linked them to around 200 associated hieroglyphics. He also deciphered the phonetic hieroglyphs for the word "Ptolemy." However, he suspected only names and foreign words were likely to be phonetic and that other hieroglyphs were symbolic.

When Champollion looked at Young's work, he disagreed. Hieroglyphs, he was convinced, were a decryptable alphabet. He systematically matched the ancient Greek and Coptic words against the hieroglyphs, slowly chipping away at the sounds. Lore has it that when he first realized he'd deciphered the whole text, he fainted for a week. Though that's likely a myth, soon after, he announced his discovery at the Académie des Inscriptions et Belles-Lettres in Paris, where rival Young would hear his discovery.

The translation of the Rosetta stone essentially created the field of Egyptology and allowed scholars to understand the sophisticated civilization that emerged on the banks of the Nile more than 5,000 years ago and persisted for millennia.

Thanks to the Rosetta stone, we have uncovered the elaborate rituals and religious beliefs that governed life and death in the Book of the Dead, have re-created the complex embalming recipes the ancient Egyptians used to mummify the dead, have a detailed picture of day-to-day life for royals and commoners alike, and have untangled the histories of dynasties that ruled for thousands of years.

The Rosetta stone was taken as a spoil of war and is still housed at the British Museum, but it remains a central piece of Egypt's heritage. For many years, Egypt has called for the artifact to be returned to its homeland.