Sed-festival (Heb-Sed)A feast known from the Predynastic to the Ptolemaic period, which centred around renewal of physical and magical powers of the ruling king. Presumably a king's first Sed-festival was held in or around his thirtieth year on the throne or when it was deemed necessary. After that, it could be repeated every two or three years. Since written sources about the festival, despite being manifold, are non-specific and little informative, much remains unknown. Even the etymology of sed is unclear; it may refer to the god Sed, an animal tail or a specific piece of clothing. It is known that the king, the main participant, wore a short robe, either the Upper or Lower Egyptian crown (never combined) and often the crook and flail. Special buildings and installations existed for the festival. Several rituals were performed during the feast, including one where the king would run a circuit (presumably to prove his physical abilities). Scenes of the festival were a fixed motif on funerary temples, where the depictions magically enabled the king to renew his powers continually. A large part of the complex surrounding Djoser's Step Pyramid at Saqqara was built for such a symbolic enactment of the festival.