About 2700 BC the existence of a new, powerful, centralized state was memorialized for eternity in the building of an extraordinary funerary monument for a king named Zozer. This monument was the Step-Pyramid complex, which was erected at Saqqara. Zozer was the second king of the Third Dynasty, but it is with him that the "Old Kingdom" truly began. The Old Kingdom was the first great era of the royal state of Egypt, an era in which powerful autocrats so dominated the resources of the Nile Valley that they could devote themselves to the achievement of extraordinary works of monumental art and architecture.
Four dynasties reigned during the Old Kingdom Period. The Third was the era of the Step-Pyramid complex, only one of whichthat of Zozerwas ever completed. The Fourth Dynasty was the age of the true pyramid, signified by the construction of the two pyramids of King Sneferu at Dashur and by the pyramids of Khufu, Khafre, and Menkaure at Giza. The Fifth and Sixth Dynasties were characterized by pyramid complexes built at Abusir and Saqqara, which, though smaller in size than those of the Fourth Dynasty, represented a major step forward in the evolution of engineering techniques. These various funerary monuments served not only the king's spirit in the afterlife but also acted as advertisements of the power of the monarchy.

For the Egyptian kingship was a divine kingship. and the oldest surviving monumental stone temples of Ancient Egypt are the great temple-tombs of the monarchs of the Old Kingdoms. The cult of the king amounted to the apotheosis of the state itself. The best evidence for this is that before the Fifth Dynasty no major temple structures other than the royal tomb complexes were constructed on a monumental scale, neither in brick nor in stone. Most Old Kingdom temples seem to have been small structures built of brick and located in the midst of densely-packed villages and towns. It is true that in the Fifth Dynasty several kings built at the site of Abusir (near Saqqara) large, stone temples dedicated to Ra, the Sun-God, but these temples were adjuncts to pyramid complexes also built at Abusir and cannot be separated from them.

It appears that, during the Third Dynasty, the cult of the king was characterized by an ideology that focused on kingship itself. To worship the king was a political act, for it was an acknowledgment of royal authority and legitimacy. In the Fourth Dynasty, the royal cult appears to have altered so as to acknowledge the direct association of the king with the greatest and most powerful of the forces of nature: Ra, the sun. The alteration of the form of the pyramid from the stepped shape of the Third Dynasty to the "true" pyramid shape of the Fourth Dynasty may have followed from this merging of the solar cult with the cult of kingship. The efforts of Fifth Dynasty kings to build huge solar temples near their pyramid complexes at Abusir further attests to the state's apotheosization of itself in the form of the sun. The greatest achievement of the Old Kingdom state was its development of a bureaucracy so extensive and so efficient that it could manage the astonishing logistical problems associated with that the construction of the pyramid complexes. This was still a primitive society lacking in technological expertise and sophistication, but the building of the pyramids was a triumph of organization and management, both on site and in the bringing together and provisioning of craftsmen and laborers. Moreover, as time passed and Egyptian engineers gradually became more knowledgeable in their manipulation of stone materials, the Egyptian began to experiment with buildings composed primarily of walls, columns, and beamsbuildings that (unlike the pyramids) were no longer artificial mountains but that featured larger and larger columned hallways. The eventual decline of the Old Kingdom state is often (and erroneously) correlated with the fact that the pyramids of the Fifth and Sixth Dynasties are of considerably lesser volume than those of the Fourth Dynasty, as if the equation of pyramid size with the stability of the regime is a valid guide to historical process. In fact, it is not, for the lesser volume of the later pyramids follows from a shift in priorities brought about by important advances in the science of engineering. In the Fifth and Sixth Dynasties the Egyptians began to master the art of erecting monumental stone structures that enclosed substantial volumes of empty space. They had also learned how to employ free-standing columns to support stone or wooden roofs and to create huge hallways, with the consequent effect of providing vastly-increased wall space for decoration. Indeed, it is likely that the resources required to build and decorate a Sixth Dynasty pyramid complex were as great as those required to build a Fourth Dynasty complex.
However, the problem of the
decline of the Old Kingdom state remains. It appears to have occurred rapidlywithin
a generation or twofor something seems to have happened around the year
2200 BC that wrecked the centralized state of the Old Kingdom and left the
Nile Valley broken up into a series of competing regional principalities.
What this "something" was cannot be clearly identified, but many
scholars have argued that the Old Kingdom gave way to centripetal political
forces that had been threatening to tear the state apart for yearsforces
that represented the growing power of the Egyptian nobility. However, the
evidence for this explanation is poor. A more recent theory maintains that
the collapse of the Old Kingdom was brought about by natural disaster, as
several decades of consistently low Nile floods led to famine, economic
disorder, and the breakdown of the royal bureaucracy. There is firm evidence
of a long period of low Niles around the year 2200 BC, and periods of natural
disaster such as that described above are known to have occurred during
other, more recent periods of Egyptian history.