The Assassin's Creed franchise spans over hundreds of years from Greek times all the way to modern day and in that timeline you might have missed a game or two or didn't finish them which is why you need to check out this timeline video before playing Assassin's Creed Odyssey.
The timeline video below spans from Assassin's Creed Odyssey to Syndicate, specifically the animus parts of the game where you go back in time. It all connects so you can save some time and go straight to playing Odyssey! Check it out below!