Beginning of the 4th Dynasty (2575-2465)
Despite the millennia-long fascination with the three immense pyramids on the Giza plateau, the greatest pyramid builder of the 4th dynasty (and, indeed, of all Egyptian history) was neither Khufu nor Kafre nor Menkaure. It was their predecessor, the first king of the 4th dynasty, Snefru (2575-2551), who constructed as many as five pyramids, three of them turning points in the develop- ment of pyramid archi- tecture.
Snefru's first attempt, at Meidum, resulted in what came to be called the Collapsed Pyramid or, sometimes, the False Pyramid. The start of this pyramid's construction was long attributed to Huni (2599-2575), the last king of the 3rd dynasty, and the completion to Snefru. Archeological opinion is shifting, however, to a conviction that Snefru is solely responsible for the pyramid. It seems of a piece with the trial-and-error progress of his other pyramids, located at Dashur.
The great mound of debris at the base of the Collapsed Pyramid is what is left of what may have been an 8-step pyramid, the first (and only?) such structure after Djoser's. It was never used as a tomb and perhaps had never been intended as such. Some students think it could have been an early Sun Temple, with an obelisk jutting out the top. And many are convinced that Snefru intended to add casing stones that would have filled in the steps to make it into a true pyramid.
At any rate, it was abandoned before it came to any sort of genuine completion. Snefru moved on to new projects at Dashur.