The ancient Egyptian written language is called hieroglyphics.

Eventually, no one knew how to read these hieroglyphics. The Rosetta stone is a stone tablet found in Egypt by Napoleon's army in the about 1800. The Rosetta stone had on it the same inscription text in hieroglyphics, Greek, and Coptic (Egyptian with Greek influence). It took many years, but the ancient Egyptian hieroglyphics were eventually deciphered and could be read. Today, the term Rosetta stone is a term or symbol for the key to solving an important problem.