The Old Kingdom spans Egypt's Third through Sixth Dynasties, conventionally dated from around 2686 to 2181 BCE, and is remembered above all as the age of pyramid building. Djoser's Step Pyramid at Saqqara, designed by the official Imhotep in the Third Dynasty, was the first large stone monument in Egyptian history and set the pattern that culminated in the Fourth Dynasty with the true pyramids of Sneferu at Dahshur and, above all, the Great Pyramid of Khufu at Giza, built as the king's tomb and the physical expression of his claim to an eternal afterlife among the gods. The pyramid complex, with its mortuary and valley temples, causeway and subsidiary structures, mobilized a workforce and an administrative bureaucracy on a scale unmatched anywhere else in the contemporary world.
Royal power weakened through the Fifth and Sixth Dynasties as provincial governors, the nomarchs, accumulated local authority and their own funerary resources, a shift visible in the increasingly modest scale of royal pyramids set against increasingly elaborate provincial tombs. The Old Kingdom ended in the political fragmentation of the First Intermediate Period, a collapse Egyptian tradition later blamed on the exceptionally long reign of Pepi II and which modern scholarship also links to a weakening Nile flood cycle. The Oxford History of Ancient Egypt, edited by Ian Shaw, remains the standard modern synthesis of the period's political and building history.