So first let's think about the center of power. Well, the Roman Empire is named after its seat of power during the great majority of its history. The seat of power of the Roman Empire is Rome. Near the end of the Western Roman Empire, it becomes Ravenna. And of course we talk about Constantine changing the capital to Byzantium, which eventually became Constantinople. And that's the official start of at least the roots of the Byzantine Empire, although Constantine was emperor of both. It's fair to say that Rome was the capital of the Roman Empire from its early days as a kingdom all the way until the first several centuries of the Common Era.