Thravid, while I 100% love the Romans and their history, I would have to disagree with this. The Roman Empire doesn't have to be formed, it is literally already in the game. It is the Byzantium Empire. The Byzantium Empire was the Roman Empire.
Originally there was the Roman Kingdom(I believe before them it was Alba Longa or something?). After the monarchy was overthrown(and unfortunately a lot of information lost in fire), it became the Roman Republic. After Julius Caesar, it became the Roman Empire. Eventually it was split into a West Empire and an East Empire, yet, it was still the same Empire. It wasn't truly a full on divide the Empire into two separate Empires, it was more of an administrative division. Well, actually, it was 4 administrative Divisions the Empire was split into, but you get my point. But it was actually merely 2 halves of a whole. Though note, Theodosius I still ruled over both Empires before his death. He was the last one to rule over both.
But after the fall of the Western Division of the Empire, the Eastern Division still survived for a long time. And the terms Byzantium Empire and Eastern Roman Empire were actually only used AFTER it fell. At that time they were still known as the Roman Empire. Hell, at a time they even managed to regain about halve of the former Roman Empire's territory. Well, more like 2/3'rds, including Italy, most of the northern coast of Africa, the southern part of what is now Spain, etc.
So yes, the Roman Empire is literally in the game, but by the name of the Byzantium Empire.