The Nile Valley seems to have been inhabited at a remote period by Neolithic men in the barbarian stage of culture. They made beautiful implements of polished flint, fashioned pottery, built in brick and stone, sailed boats on the Nile, introduced such useful animals as the buffalo, ass, and goat, and tilled the soil. In time, they began to smelt copper and to write by means of phonetic signs.
Both metallurgy and sound writing arose in Egypt earlier than anywhere else in the world. The Neolithic Egyptians must have lived at first in separate tribes, under the rule of chiefs. As civilization advanced, the tribal organization gave way to city-states, that is, to small, independent communities, each one centering about a town or a city.
The city-states by 4000 B.C. had combined into two kingdoms, one in the the builders of these mighty structures. The most celebrated monarch of this time was the Pharaoh Khufu, whom the Greeks called Cheops. The Great Pyramid which he erected for his tomb remains a lasting witness to his power. Though we know little of Khufu and his successors, the Egypt over which they ruled must have been the home of a highly gifted and civilized people.
Egypt occupies an isolated position, being protected by deserts on each side, by the Mediterranean on the north, and by the cataracts of the Nile (impeding navigation) on the south.
Thus sheltered from the inroads of foreign peoples, the Egyptians enjoyed many centuries of peaceful progress. The old city of Memphis gradually declined in importance, and Thebes in Upper Egypt became the capital of the land.