The following table embodies the chief available data :
The drain on the country’s resources did not end when the pyramid complex was completed ; for a large staff of priests, overseers, and other officials were maintained, not only during the king’s lifetime but also for some centuries after his death. It was inevitable that such a state of affairs could not long continue, and the system eventually collapsed for economic and other reasons. Some of the kings were not above rewarding their favourites with funds misappropriated from the mortuary endowments of their predecessors.
With the passage of time each pyramid complex tended to be built smaller and smaller, and more and more crudely, although some exceptions there naturally were. By the latter part of Dynasty XII the main body of pyramids had degenerated to mud-brick, limestone being reserved merely for the internal chambers and passages and external casing. After Dynasty XIII no more pyramids were built, except some very degenerate examples not to be compared with those of the Old and Middle Kingdoms. Very soon afterwards the whole sixty-mile range of pyramids from Gîza to Maidûm had become a desert solitude.
extrait d' Egyptian Pyramids, 1947, par Leslie Grinsell (1907-1995), archéologue et conservateur de musée anglais. Durant la Seconde Guerre mondiale, il a rejoint la Royal Air Force et a servi en Égypte, où il s'est familiarisé avec les vestiges archéologiques de l'Égypte antique.