Bayek of Siwa becomes one of the early founders of the Hidden Ones in Assassin's Creed Origins.
Bayek is a Medjay, a protector and lawkeeper in Ptolemaic Egypt. His investigation into the death of his son Khemu draws him into a conspiracy involving the Order of the Ancients, the organization that predates the Templar Order.
Bayek and Aya establish the Hidden Ones near the end of the story, creating the institutional tradition that later becomes the Assassin Brotherhood. Aya is a crucial co-founder and playable character, but Bayek is the game's principal protagonist. Senu, meanwhile, is Bayek's eagle companion and helps him survey locations; Senu is not the human founder.