Hieroglyphic writing was used as far back as 3000 B.C. Its use dissipated in approximately 300 B.C. with the reign of the Greek Ptolemies. The language was dead and indecipherable until 1799, when the Rosetta Stone was found.

The Rosetta Stone is a basalt stone that was found in Raschid, Egypt. It is now in the collection of The British Museum in London.  It is inscribed  with a decree from the priests of Memphis to honor Ptolemy V.  The same decree is written in Egyptian hieroglyphs, Demotic and Greek.  At the time that it was written, the hieroglyphs were used only in highly formal religious texts, in the way Latin is used in official Catholic Decrees.  Because the text on the Rosetta Stone was also written in Greek, a living language, it was possible to deduce the meaning of the hieroglyphic text.

In 1822, French linguist and Egyptologist, Jean Francois Champollion (1790-1832) began the process of deciphering the hieroglyphic texts.  It is through his effort, and the efforts of others, that hieroglyphic texts are understood today.

The Egyptian language, some believe, originated from Sumerian, a pictogram-inspired language. Egyptian is closely related to Semitic languages.  It shares similarities in terms of root words, genders, and pronouns.  Throughout the time span in which the Egyptian language was used, it evolved into various forms:

OLD EGYPTIAN
1st -8th Dynasties (3180-2240 B.C.)
The Pyramid Text is an example of the writing of this period.
 
 

MIDDLE EGYPTIAN
9th-11th Dynasties (2240-1990 B.C.)
It was during this era when the language was refined.  It is therefore, considered the "classical" form of the language.  Most religious and literary texts are written in this form.
 
 

NEO-EGYPTIAN (also called Late Egyptian)
18th-24th Dynasty (1573-715 B.C.)
Influenced by foreign words, this form was used in business documents. Some literary texts and official monuments were also written in this form.
 
 

DEMOTIC
(715 B.C.-470 A.D.)
A script form of writing which evolved from the hieratic style of writing.  With more influence from foreign words, it was used in books and written documents.
 
 

COPTIC
(300 A.D.-600 A.D.)
The final evolution of the Egyptian language.  Texts are presently recited in the Egyptian Coptic Christian Church but it is not understood.  It is written using the Greek alphabet with the addition of seven letters inspired by hieroglyphs/hieratics.  Coptic has several dialects.  The three most important are Akhmimic, Sahidic, and Bohairic.