early death of the king. The plan of the unfinished building had to be basically changed and a decision was taken to hastily convert the unfinished pyramid, (of which only the incomplete lowest step of the core was built), into a "square-shaped mastaba" or, more precisely, a stylized primeval hill. At the moment of the king's death neither the burial apartment was built, nor was the foundation of the mortuary temple laid. Furthermore, two historical sources conform with the hypothesis of a short reign: the mason's inscription in Neferefre's pyramid was discovered "at about two thirds of the height of the extant core of the monument" and probably refers to Neferefre's first or second year on the throne; and the Turin canon which credits Neferefre with less than two full years of reign. The combination of archaeological and historical evidence led to the consensus that Neferefre's reign lasted "not longer than about two years". Building activities Pyramid complex Pyramid Neferefre started the construction of a pyramid for himself in the royal necropolis of Abusir, where his father and grandfather had built their own pyramids. It was known to the Ancient Egyptians as Netjeribau Raneferef meaning "The bas of Neferefre are divine". Planned with a square base of , the pyramid of Neferefre was to be larger than those of Userkaf and Sahure, but smaller than that of his father Neferirkare. Upon the unexpected death of Neferefre, only its lower courses had been completed, reaching a height of c. . Subsequently, Nyuserre hastily completed the monument by filling its central part with poor quality limestone, mortar and sand. The external walls of the building were given a smooth and nearly vertical covering of gray limestone at an angle of 78° with the ground so as to give it the form of a mastaba, albeit with a square plan rather than with the usual rectangular shape. Finally, the roof terrace was covered with clay into which local desert gravels were pressed, giving it the appearance of a mound in the surrounding desert, and indeed it was by the name "the Mound" that the monument was subsequently called by the Ancient Egyptians. Verner has proposed that the monument was completed this way so as to give it the form of the primeval mound, the mound that arose from the primordial waters Nu in the creation myth of the Heliopolitan form of Ancient Egyptian