The Templars are the traditional ideological rivals of the Assassins in the Assassin's Creed series.
The two factions differ mainly over how society should be organized. The Templars generally seek order and control, often believing that peace requires strong authority. The Assassins defend free will and oppose domination, summarized by their maxim: “Nothing is true, everything is permitted.” The conflict is presented across many historical eras rather than as one single war.
In the modern storyline, Abstergo Industries serves as the Templar organization and uses corporate power and technology to pursue its goals. Earlier historical groups have different names: the Hidden Ones are the predecessors of the Assassins, while the Cult of Kosmos is a separate organization in Odyssey. The Knights Templar of medieval history inspired the series' faction, but the games create a fictional secret history around them.