How did the ancient Egyptian civilization come to an end?
The last Pharonic dynasty, the Ptolemeys, were extinguished when Antony and Cleopatra lost the battle of Actium to Ocatavian (later called Augustus). Egypt became a Roman province, and it’s distinctive culture was slowly eroded. Changes in religion also put an end to many distinctive features of Egyptian civilization. The decision by Constantine and later emperors to make Christianity first favored, and then mandatory, destroyed the traditional Egyptian religion, ending a cultural tradition over 3,000 years old. Later, when Egypt was conquered by Arab Muslims, even more of the distinctive features of Egyptian civilization disappeared, including the Egyptian language. So the end of Egyptian civilization occurred in various steps, in a process lasting several centuries.