Ancient Egyptian history covers a continuous period of over three thousand years. To put this in perspective - most modern countries count their histories in hundreds of years. Only modern China can come anywhere near this in terms of historical continuity.
Egyptian culture declined and disappeared nearly two thousand years ago. The last vestiges of the living culture ceased to exist in AD 391 when the Byzantine Emperor Theodosius I closed all pagan temples throughout the Roman Empire.
It was not until Napoleon's invasion of Egypt in 1798 that the wonderful artefacts of the Egyptians were seen in Europe and their ancient culture began to awaken from its long slumber. In 1799 a French captain named Pierre Bouchard discovered the Rosetta Stone which was carved with the same text in two languages, Egyptian and Greek, and three writing systems, hieroglyphic, demotic, and the Greek alphabet.
This was a tremendous piece of luck because it enabled scholars to unlock the hieroglyphic code and without the stone, we would know nothing of the ancient Egyptians, and the details of their three thousand years of history would remain a mystery.
The man who did more than any other to recover the words of the ancient Egyptians was Jean-François Champollion. He was an historian and brilliant linguist and by the age of sixteen had mastered not only Latin and Greek but six ancient Oriental languages, including Coptic, which was the late form of ancient Egyptian.
Champollion had a unique advantage over others in the task of cracking the hieroglyphic code. Because he understood Coptic he was able to translate the meanings of the ancient Egyptian words.
In the 1820s, Champollion established an entire list of Egyptian symbols with their Greek equivalents and was the first Egyptologist to realize that the symbols were not only alphabetic but syllabic, and in some cases determinative, meaning that they depicted the meaning of the word itself.