What is the name of the Assassin Brotherhood's main rival organization in Assassin's Creed?

The Templar Order is the Assassin Brotherhood's main rival organization in Assassin's Creed.

Across the series, the Templars generally seek order and control, while the Assassins defend human freedom and individual choice. Their conflict is presented as an ideological struggle rather than a simple dispute between identical historical armies.

The games adapt the name and influence of the medieval Knights Templar into a long-running fictional organization. In the modern era, Abstergo Industries commonly acts as the Templar front or successor organization.

The Hidden Ones are an earlier name for the Assassin organization in Assassin's Creed Origins, so they are not the rival answer. The Cult of Kosmos belongs specifically to Assassin's Creed Odyssey, while Abstergo Entertainment is a subsidiary within the broader Abstergo structure.