Bayek of Siwa is the Assassin's Creed Origins protagonist who becomes a founding figure of the Hidden Ones.
Bayek is a Medjay from the Siwa Oasis in Ptolemaic Egypt. The game follows his pursuit of people responsible for personal loss while he becomes entangled in a larger political and secret conflict. His wife, Aya, is also a major character and an important participant in the creation of the new organization.
Origins is set mainly during the first century BCE, when Cleopatra VII and Ptolemy XIII contest control of Egypt. The story uses this period to explain how the Hidden Ones emerged as an early form of the Assassin Brotherhood.
The name “Assassin” is not the organization’s standard name in Origins. The Hidden Ones are its earlier incarnation, and their principles later develop into the recognizable Assassin Brotherhood. Senu, Bayek's eagle, is an animal companion rather than a human protagonist.