In what war is Assassin's Creed Odyssey's historical story primarily set?

Assassin's Creed Odyssey is primarily set during the Peloponnesian War between Athens and Sparta.

The game begins in 431 BCE, the year traditionally associated with the outbreak of the conflict. Players travel through the Greek world as a mercenary connected to the Spartan and Athenian sides, encountering historical figures, military campaigns, political factions, and legendary locations.

The real Peloponnesian War lasted from 431 to 404 BCE, with Sparta and its allies ultimately defeating Athens and the Delian League. Odyssey adapts this setting for an open-world adventure, combining documented historical events with fictional family drama, mythology, and the series' Isu storyline.

The conflict is sometimes confused with the earlier Persian Wars, which involved Greek states resisting the Persian Empire in the fifth century BCE. Those wars had already ended before Odyssey's main period begins.