A branch of archaeology specializing in the investigation of ancient Egyptian civilization, especially the study of pharaonic Egypt (c 4500 BC-641 AD) and its relics. Some scholars date the beginning of the discipline September 1822, when Jean-François Champollion wrote his "Lettre a Dacier relative a l'alphabet des hierglyphes phonetiques" in which he demonstrated that he had deciphered the hieroglyphic script. Others say Egyptology began when the scholars accompanying Napoleon Bonaparte's invasion of Egypt (1798-1801) published the "Description de l'Égypte" (1809-28) which made large quantities of source material about ancient Egypt available to scholars.