Found in 1799 & used as a key for translating Ancient Egyptian hieroglyphics
Fun Facts
When the Rosetta Stone was discovered, no one knew how to read ancient Egyptian hieroglyphics.
The Rosetta Stone has a decree from King Ptolemy V written in three different languages: hieroglyphics, demotic (a cursive Egyptian script used at the time) and Ancient Greek.
The stone was found by the French when Napoleon invaded Egypt. His men were digging to construct a fort and found it. The British acquired the stone when Napoleon was defeated.
Jean-Francois Champollion provided a crucial step in identifying the hieroglyphics that were used to write the names of non-Egyptian rulers in 1822.