Of all the ancient written languages, Egyptian hieroglyphs have been the most mysterious. The Ancient Egyptians invented the picture language and used it for thousands of years. But after the decline and conquest of Egypt, the knowledge about hieroglyphs was lost. The language was an enigma for thousands of years. Many people studied the old writing, but none could decipher what it meant.
An article about the Rosetta Stone, which is credited for unlocking the ancient Hieroglyphic writing system.