What is the ancient Egyptian setting of Assassin's Creed Origins called?

Assassin's Creed Origins is set in Ptolemaic Egypt.

The game takes place in Egypt during the final period of the Ptolemaic Kingdom, beginning in 49 BCE. Its protagonist, Bayek of Siwa, is a Medjay who becomes involved in a conspiracy connected to the origins of the Hidden Ones, the organization that later develops into the Assassin Brotherhood.

The setting includes Alexandria, Memphis, Cyrene, the Giza plateau, and the deserts and oases of Egypt. Cleopatra VII and Julius Caesar are among the historical figures represented in the story. The game uses the political struggle between Cleopatra and Ptolemy XIII as part of its historical backdrop.

Ptolemaic Egypt was ruled by the Ptolemaic dynasty, a Greek-Macedonian royal house founded after Alexander the Great's empire was divided. The period ended when Egypt became a Roman province in 30 BCE, shortly after the deaths of Cleopatra and Mark Antony.