Ancient Egyptian civilization emerged along the Nile Valley as aresult of the unification of all Egyptians under the central authority of one single king,  the Pharaoh.Economic collapse caused the gradual decline and fall of ancient Egyptian civilizationBut the economy ofancient Egypt was ruined by all the resources that the Pharaohs put into the building of pyramids and the burial of their treasures in their own tombs.This national pride and identification with the Pharaoh kept the unity of ancient Egypt and made its civilization prosper for many centuries.The Pharaoh's government guaranteed both external and internal security to the people of Egypt .As a consequence, the Egyptians grew very proud of their country and  became so fond of the Pharaoh that they worshipped him as a God-king .