Which historical order is the main enemy of the Assassins in Assassin's Creed Origins?

The Order of the Ancients is the main enemy of the Assassins in Assassin's Creed Origins.

In Origins, Bayek and Aya investigate a secret network manipulating political power in Ptolemaic Egypt. This network is called the Order of the Ancients. Its members operate behind public identities and pursue control through influence, military force, and political intrigue.

The Hidden Ones emerge from Bayek and Aya's response to this threat. They establish principles and methods that later develop into the Assassin Brotherhood. The game therefore presents the Order of the Ancients as a predecessor organization to the Templars, while the Hidden Ones serve as predecessors to the Assassins.

The Templar Order is the later organization familiar from many other games. The Cult of Kosmos is the opposing conspiracy in Assassin's Creed Odyssey, and the Roman Senate is a political institution rather than Origins' secret enemy faction. These distinctions matter because the series uses different precursor groups in different historical settings.