Bayek of Siwa is the Assassin's Creed protagonist who begins as a Medjay in ancient Egypt.
Bayek is the central character of Assassin's Creed Origins, released in 2017. A Medjay is a protector and law-enforcement figure serving the Egyptian people, and Bayek's role places him in contact with local communities, rulers, soldiers, and religious institutions.
The game is set during the first century BCE, when Egypt is ruled by the Ptolemaic dynasty. Bayek and Aya become involved in the origins of the Hidden Ones, the organization that later develops into the Assassin Brotherhood.
Aya is a major playable character and Bayek's wife, which sometimes leads to confusion over the game's protagonist. “Of Siwa” refers to Bayek's home region, the Siwa Oasis in western Egypt, rather than a modern surname.