The Hidden Ones are the historical predecessor of the Assassins in Assassin's Creed Origins. Bayek and Aya establish the organization in the first century BCE after confronting abuses by powerful rulers and members of the Order of the Ancients.
The Hidden Ones adopt principles that later define the Assassin Brotherhood, including operating from the shadows and resisting control by rulers who seek absolute power. Their emblematic methods and hidden bases foreshadow the organization seen in later historical periods.
Origins deliberately presents this formation as an in-universe origin story rather than claiming that the real-world Assassin order began in ancient Egypt. The series' fictional history connects the Hidden Ones to the later Levantine Assassins.
The Order of the Ancients is the opposing organization in Origins and a precursor to the Templars. The Knights Templar belong to a much later period, while the Rooks are Jacob and Evie Frye's London allies in Syndicate.