Which Assassin's Creed game was the first to feature ancient Greece as its primary setting?

Assassin's Creed Odyssey was the first Assassin's Creed game to feature ancient Greece as its primary setting.

Released in 2018, Odyssey is set mainly in Greece during the Peloponnesian War, beginning in 431 BCE. Its map includes mainland regions and islands associated with the Aegean world, combining historical locations with mythological encounters.

Players choose between siblings Alexios and Kassandra as the playable mercenary. The game includes dialogue choices, branching quests, naval exploration, and role-playing systems that distinguish it from earlier entries.

Origins, released in 2017, takes place in ancient Egypt rather than Greece. Valhalla focuses mainly on ninth-century England and Norway, while Mirage centers on ninth-century Baghdad. These settings are historically adjacent in theme but are not the same setting.