This is the Rosetta Stone which was translated by Champollion in Paris in 1822. It is in three languages. This was the key to unlocking the meaning of hieroglyphs. Written in 196 BC, the bottom part is in ancient Greek, which was understood, the top Egyptian hieroglyph (unknown) the middle in demotic script. It was rediscovered by the French in 1799, and as they were defeated by the Brits in 1801, it was brought back to London. It weighs 1700 lbs. That's me in the middle of the picture.