Julius Caesar appears as a major historical character in Assassin's Creed Origins.
Origins places Caesar within its first-century BCE story about Bayek, Aya, Cleopatra, and the formation of the Hidden Ones. Caesar becomes involved in the civil and political conflicts surrounding Ptolemaic Egypt, and his alliance with Cleopatra is a major part of the campaign's historical backdrop.
The game dramatizes real events while adding fictional characters, secret organizations, and supernatural-seeming technology from Assassin's Creed lore. It is not a documentary reconstruction, so some meetings, motivations, and action sequences are shaped for the narrative. Caesar's role nevertheless reflects his real intervention in the Egyptian succession crisis and his relationship with Cleopatra VII.
Augustus, Nero, and Hadrian were also Roman emperors, but they belong to different generations. Caesar was assassinated in 44 BCE and was never formally a Roman emperor in the later constitutional sense. Origins uses him as a powerful Roman leader during the transition from Republic to imperial rule.