Which ancient war forms the historical backdrop of Assassin's Creed Odyssey?

The Peloponnesian War forms the historical backdrop of Assassin's Creed Odyssey.

Assassin's Creed Odyssey is set in Greece during the fifth century BCE, primarily in the conflict between Athens and Sparta. The war lasted from 431 to 404 BCE, although the game begins in 431 BCE and presents a fictionalized adventure across the Aegean world. Players choose Alexios or Kassandra as the playable mercenary protagonist.

Ubisoft Quebec developed Odyssey, which was released in 2018. Its map includes mainland Greece and numerous islands, with naval travel, dialogue choices, role-playing systems, and multiple possible story outcomes. Historical figures such as Socrates and Pericles appear alongside fictional characters.

The game is not set during the later Roman conquest of Greece or the earlier Persian Wars. It uses the Peloponnesian conflict as its political and military framework while adding the series' Isu mythology and fictional family drama.