The Hidden Ones are the organization that becomes the historical precursor to the Assassins in Assassin’s Creed Origins.
Bayek and Aya establish the Hidden Ones during the game’s story in first-century BCE Egypt. Their purpose is to oppose the Order of Ancients, a secretive power network that manipulates rulers and institutions. The Hidden Ones develop principles and methods that later resemble the Assassin Brotherhood’s creed, secrecy, and struggle against authoritarian control.
The Order of Ancients is therefore a different organization, not another name for the Hidden Ones. The Medjay is Bayek’s social and professional title, describing his role as a protector rather than the name of the new order. Origins presents the Hidden Ones as an early stage in the fictional history of the Assassins, while later games show how the group’s identity and public name evolve.