Pyramid of Djoser
Early evidence for the use of this royal cubit comes from the Early Dynastic Period: on the Palermo Stone, the flood level of the Nile river during the reign of the Pharaoh Djer is given as measuring 6 cubits and 1 palm. Use of the royal cubit is also known from Old Kingdom architecture, from at least as early as the construction of the Step Pyramid of Djoser designed by Imhotep in around 2700 BC.