The difficulty of imagining now what motives determined the Pharaohs to choose such different proportions has led some to think that the mass built was in direct proportion to the time occupied in building; that is to say, to the length of each reign.

Thus it was supposed that the king would begin by hastily erecting a pyramid large enough to contain the essential parts of a tomb; and then, year by year, would add fresh layers around the first core, until the time when his death for ever arrested the growth of the monument.

But the facts do not justify this hypothesis.

The smallest of the pyramids of Sakkarah is that of Unas, who reigned thirty years; while the two imposing pyramids of Gizeh were raised by Khufu and Khafra (Chephren), who governed Egypt, the one for twenty-four, and the other for twenty-three years.
Merenra, who died very young, had a pyramid as large as that of Pepi II., whose reign lasted more than ninety years (Note 16).

The plan of each pyramid was laid down, once for all, by the architect, according to the instructions which he had received, and the resources placed at his disposal.