Abydos through history: the Festival of Osiris

In the beginning of the third millennium B.C., Abydos was the domain of the pharaohs of the first two dynasties; the city was then called This. Later, probably at the beginning of the Old Kingdom when Djeser made Memphis his capital, This was renamed Abdjou, which the Greeks transcribed as Abydos.
Originally, the god Khentamenti was worshiped there; but during the 11th Dynasty, for reasons which are thought to be more political than religious, Pharaoh Antef imposed the worship of Osiris, who became Osiris-Khentamenti, Osiris, Leader of the Dead [glossary] and Lord of Abdjou.
From the time of the 11th Dynasty, the nome [glossary] and its capital acquired considerable importance benefiting from the growing support which the pharaohs accorded to the Osirian myths [glossary]]: if the exegetes are to be believed, the god's head was purportedly taken to Abydos, after his brother, Seth, assassinated and dismembered him.
On the occasion of the great annual and biennial feasts, crowds of pilgrims from all the Kingdom's nomes converged on the area around the great temple and, together, celebrated the divine mysteries, Osiris' and Seth's confrontation, the god's death at his own brother's hands, his dismemberment, Isis' pain and anger, her search for her husband's scattered pieces, the funeral and, finally, the resurrection of the Justified One, who took back his place at the head of his people and his domains. Some episodes of this Passion Play took place in the open with the active and, no doubt, rowdy participation of the hordes of pilgrims. Others, more secret or more arcane, took place inside the temple with the priests and servants as the only players.
Before starting home for their provinces at the conclusion of what had come to be known as the Festival of Osiris as dynasty followed dynasty, the pilgrims instituted the custom of offering a token of their faith to the god, a humble votive offering of dried alluvium, statuettes stelae, chapels or, if they were kings, entire temples. Abydos was at the peak of its glory during the 19th Dynasty: it was then that the great Seti I went on a pilgrimage there and also dedicated his gift, the King Menmaatre's August Castle for Millions of Years [glossary] to Osiris; this is one of the most perfect of the holy sites, but also one of the most disconcerting in Egypt.