Sparta is the family home of Assassin's Creed Odyssey's protagonist. The game begins on the Spartan island of Kephallonia before the hero's journey expands across the Greek world during the Peloponnesian War.
Players choose either Kassandra or Alexios as the protagonist. Regardless of that choice, the character is a descendant of King Leonidas I and has a direct connection to Sparta's royal family.
The historical setting is the fifth century BCE, when Athens and Sparta were leading rivals in the Peloponnesian War. Odyssey uses real places and historical figures while adding the series' fictional conflict and myth-inspired quests.
Athens is another major location and is therefore a common mix-up. However, the protagonist's family identity and opening backstory are specifically tied to Sparta, not Athens or Corinth.