Final answer:
The group that marched to and from Eleusis, escorting the "holy things" as part of the Eleusinian Mysteries, was called the ephebes. They were part of a procession led by the hierophant and the priest of the gods for whom the Mysteries were celebrated.
Step-by-step explanation:
The group that marched to and from Eleusis, escorting the "holy things" as part of the beginning of the Eleusinian Mysteries was called the ephebes, the Athenian male youth. They were part of a huge cavalcade of Greeks who held a kind of pilgrim's staff and were accompanied by their donkeys with provisions and torches. The procession was led by the hierophant and the priest of the gods for whom the Mysteries were celebrated. The procession included priestesses carrying sacred objects on their heads and was followed by a large crowd chanting hymns and invoking the god lakchos.