The Pyramids’ enigma has puzzled people ever since they were built. Whereas the Ancient Greeks vaguely understood their function, the Romans were less certain; medieval Arabs believed them to be treasure houses with magical guardians; and early European observers reckoned them the biblical granaries of Joseph. Most archeologists now agree that the Pyramids’ function was to preserve the pharaoh’s ka, or double: a vital force which emanated from the sun god to his son, the king, who distributed it amongst his subjects and the land of Egypt itself. Mummification, funerary rituals, false doors for his ba (soul) to escape, model servants (shabti figures) and anniversary offerings – all were designed to ensure that his ka enjoyed an afterlife similar to its earthly existence. Thus was the social order perpetuated throughout eternity and the forces of primeval chaos held at bay, a theme emphasized in tomb reliefs at Saqqara. On another level of symbolism, the pyramid form evoked the primal mound (benben) at the dawn of creation, a recurrent theme in ancient Egyptian cosmogony. This was represented first by megalithic benben stones, then obelisks, whose pyramidal tips were sheathed in glittering electrum (an alloy of silver and gold), and finally pyramids, topped by electrum-covered pyramidion capstones, as seen in the Egyptian Museum.