The Hidden Ones are the historical predecessor of the Assassin Brotherhood in Assassin's Creed lore. Bayek and Aya establish the group in Assassin's Creed Origins during the first century BCE, after the deaths of their son and their confrontation with the Order of the Ancients.
The Hidden Ones develop principles that remain central to later Assassins, including protecting freedom and operating from the shadows. Members use hidden blades and secret bureaus while opposing rulers and institutions that seek control through the Pieces of Eden.
The Order of the Ancients is their enemy rather than their predecessor. It is an older secret organization that later develops into the Templar Order. Over the centuries, the Hidden Ones evolve into the Assassins, with terminology and organizational structures changing across different historical periods.