The pyramids are one of the most enduring images of ancient Egypt. These monumental stone tombs were part of the funerary complexes of the kings of the Old and Middle Kingdoms. Their form developed from the rectangular mastaba tombs of the kings of the Early Dynastic period. The first pyramid, the Step Pyramid of Djoser, consists of six tiers that are like mastabas of decreasing size stacked one on top of the other.
The most famous pyramids are those at Giza, built by the kings Khufu, Khafre and Menkaure of the Fourth Dynasty (about 2613-2494 BC). These are 'true pyramids', with smooth sides, and were part of large funerary complexes including a mortuary temple, valley temple and causeway. Each complex had a harbour and canal linking it to the Nile. The Giza pyramids are of solid construction, but in the Fifth and Sixth Dynasties the core of the pyramid was usually of rubble with retaining walls, made smooth by an outer limestone casing. The core of Middle Kingdom (Twelfth Dynasty) pyramids was either rubble or mud brick.
In the New Kingdom (about 1550-1070 BC), the funerary chapels of private individuals often had pyramids above them. These were smaller than royal pyramids and had steeper sides. The pyramid was revived as a royal funerary structure by the Kushite kings of the Twenty-fifth Dynasty (about 747-656 BC), who were buried in Sudan. These pyramids more closely resemble the private structures of the New Kingdom than the royal monuments of the Old and Middle Kingdoms.