The unification of the northern kingdom with the South seems to have been a slow process, interrupted by insurrections and rebellions in the Delta and in Lybia. Inscriptions report the suppression of these insurrections and give the number of war-captives brought to the south as slaves. In one instance the captives numbered 120,000 in addition to 1,420 small cattle and 400,000 large cattle. Using these war captives to supplement the home supply of forced and free labor, successive dynasties built temples, palaces and tombs; constructed new cities; drained and irrigated land; sent expeditions to the Sinai peninsula to mine copper. Such enterprises indicate a considerable economic surplus above that required to take care of a growing population: the high degree of organization required to plan and assemble such enterprises, and the considerable engineering and technological capacity necessary for their execution. Chief among the binding forces holding together the extensive apparatus known as the Old Kingdom was religion, with its gods, its temples and their generous endowments. Each locality consolidated into the Old Kingdom had its gods and their places for worship. In addition to these local religious centers there was an hierarchy of national deities, their temples, temple lands and endowments. The ruling monarch, who was official servitor of the national gods, interpreting their will and adding to the endowments of the temples, was the embodiment of secular and of religious authority. Egyptians of the period believed that death was not an end, but a transition. They also believed that those who passed through the death process would have many of the needs and wants associated with life on the Earth. Furthermore they believed that in the course of their future existence those who had died would again inhabit the bodies that they had during their previous existences on Earth. Following out these beliefs the Egyptians put into their tombs a full assortment of the food, clothing, implements and instruments which they had used during their Earth life. They also embalmed the bodies of their dead with the utmost care and buried them in carefully hidden tombs where they would be found by their former users and occupied for the Day of Judgment. Holding such views, preparation for the phase of life subsequent to death was a chief object of the early Egyptian rulers and their subjects. One of the preoccupations of each new occupant of the throne was the selection of his burial place. Early in his reign he began the construction of suitable quarters for the reception of his embalmed body. The great pyramids were such tombs. Other monarchs constructed rock-hewn chambers for the reception of their bodies. In these chambers in addition to a room for a sarcophagus were associated rooms in which every imaginable need of the dead was stored: food, clothing, furniture, jewelry, weapons.