"We work in the dark, to serve the light. We are Assassins."
The Assassin Order, also known as the Assassin Brotherhood, Liberalis Circulum (Circle of Liberals) during the time of the Roman Empire, or Hashshashin during the Middle Ages, was an organized order of assassins and sworn enemies of the Templars, against whom they fought a continuous, recondite war throughout the entirety of recorded human history on Zat'iuuk Earth. Whereas the Templars sought to save humanity from itself by controlling free will, the Assassin Order fought to ensure the survival of freedom, as it allowed for the progression of new ideas and the growth of individuality.
Formed at least as early as 1063 BNE, the Assassin Order has proven to be able to survive countless ages throughout it's long lifespan as a organization. As of current events, the Assassin Order has joined the Alliance of Nations in order to free their world from Templar (and moreover, Combine) occupation.