In Assassin's Creed Odyssey, which ancient war forms the main historical setting?

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

The game is set in ancient Greece from 431 to 422 BCE, during the early part of the war between Athens and Sparta. The player controls a mercenary named Alexios or Kassandra, and the choice affects the playable character while the broader historical setting remains the same.

Odyssey presents a large open world containing mainland Greece and many Aegean islands. Historical figures such as Pericles, Socrates, and Brasidas appear alongside fictional characters and the series' Isu mythology. The player can support either the Athenian or Spartan side in different military engagements.

The real Peloponnesian War lasted from 431 to 404 BCE, ending with Spartan victory. Odyssey uses the war as a framework rather than attempting to reproduce every event in exact chronological detail, allowing branching quests and player choices within its historical-fiction structure.