Parthian Empire

The Parthian Empire is a major power that exists from the very start of the game until around 222.

Though not as powerful as the Roman Empire, Parthia is still a very strong country and can easily exert influence in its own right, especially since it controls the rich provinces of Mesopotamia, and also has a large diversity of resources, not to mention its high max province cap of 50.

A good initial strategy for the Parthian Empire is to try to ally Rome once their initial war is complete (to win that, you can simply fight defensively and hope Rome is unable to peace you). After you ally Rome, expand into Arabia and India, but don't antagonize Rome, as doing that will have grave consequences.