What is the name of the first Assassin's Creed game centered on ancient Greece?

Assassin's Creed Odyssey is the series game centered on ancient Greece.

Released in 2018, Odyssey is set during the fifth century BCE, in the era of the Peloponnesian War between Athens and Sparta. Players explore a large version of the Greek world, including mainland regions and many Aegean islands.

The player chooses between Kassandra and Alexios as the main character. Kassandra is the canonical protagonist in the game's novelization, while the game itself allows either sibling to be selected. This choice is why a question about the game's title has a more definite answer than one asking for its protagonist.

Odyssey follows the character's family history and encounters with the Cult of Kosmos, an organization connected to the broader series mythology. It is set centuries before Origins and does not depict the Assassin Brotherhood in its later established form.

The game also includes dialogue choices, naval travel, mercenary systems, and role-playing mechanics.