I think the greatest civs are: Rome, Byzantines, Portuguese, England, America and Arabs. Why? Rome- Theier UU is the best in the Anicent Times and it can be used in the beggining of the middle ages Byzantines-The reason is also about theier UU. The Dormon is the "king of seas" in all Anicent Times and i sinked many times caravels and frigates with it Portugal- Really the reason is not by being my country, but mostelly by the traits. Expansionist civs are good at pangea maps, and seafarings in Islands so the combination of the 2 is perfect to continents. And the UU doen't sink on the ocean because of that I can take Advantage on Navigation( I like to the color) The other 2 are good too.