Egypt's history dawns on a well-organized society: The Old Kingdom, based on the productivity of the narrow, lush Nile Valley. The products of the Valley were sufficient to maintain a large population of cultivators: some slave, some forced labor, about which we have little knowledge; a bureaucracy, headed by a supreme ruler whose declared divinity was one of the chief stabilizing forces of the society. Between its agricultural base and its ruling monarch, the Old Kingdom had a substantial middle class which procured the wood, stone, metals and other materials needed in construction; a corps of engineers, technicians and skilled workers, and a substantial mass of humanity which provided the energy needed to erect the temples, monuments and other remains which testify to the political, economic, and cultural competence of the ruling elements and the technical skills present in the Old Kingdom. Foremost among the factors responsible for the success of the Old Kingdom was the close partnership between the "lords temporal" and the "lords spiritual"--the state and the church. The state consisted of a highly centralized monarchy ruled by a Pharoah who personified temporal authority. This authority was strengthened because it represented a consensus of the many gods recognized and worshiped by the Egyptians of the Old Kingdom. The monarch was also looked upon as an embodiment of divinity. Some Egyptian pharoahs had been priests who became rulers. Others had been rulers who became priests. The two aspects of public life--political and religious--were closely interrelated. In theory the land of Egypt was the property of the Pharoah. Foreign trade was a state monopoly. In practice the ownership and use of land were shared with the temples and with those members of the nobility closest to the ruling monarch. Hence there were state lands and state income and temple lands and temple income. The use of state lands was alloted to favorites. Each temple had land which it used for its own purposes. Political power in the Old Kingdom was a tight monopoly held by the ruling dynasty of the period. During preceding epochs it seems likely that rival groups or factions had gone through a period of power-survival struggle which eliminated one rival after another until economic ownership and political authority were both vested in the same ruling oligarchs. This struggle for consolidation apparently reached its climax when Menes, a pharoah who began his rule about 3,400 B.C., in the south of Egypt, invaded and conquered the Delta and merged the two kingdoms, South and North, into one nation which preserved its identity and its sovereignty until the Persian Conquest of 525 B.C.