The Rosetta Stone is a black slab of granodiorite, slightly taller than a metre.
Found in 1799 by French soldiers half-buried in a fort wall near the Egyptian town of Rosetta, it carries the same text in three scripts: hieroglyphics at the top — the formal script of temples, tombs and monuments, reserved for gods and pharaohs — Demotic in the middle, the everyday cursive script used by ordinary Egyptians for documents and records, and Greek at the bottom, the language of the ruling class since Alexander the Great conquered Egypt in 332 BC.
It held the key to deciphering hieroglyphics, which had eluded comprehension for nearly 1,400 years.
The breakthrough came in 1822.
Jean-François Champollion, a French scholar who had been obsessed with ancient Egypt since childhood, cracked the code by working across all three scripts — using the Greek, which scholars could already read, to decode the Demotic, and the Demotic to unlock the hieroglyphics.
He worked out that hieroglyphics were not purely symbolic — some signs represented sounds.
He reportedly ran to his brother's office, gasped 'I've got it!', and fainted.
The text itself is a decree from Ptolemy V, thanking priests for their loyalty.
Its decoding handed us a priceless key to 3,000 years of Egyptian history.
Fun fact: most visitors are surprised by how small it is.
It is also not black — centuries of handling have polished it to a dark grey sheen.
The original colour was probably a dark greenish-blue.
