By the time of Diocletian in the late 3rd century, it was already clear that Rome no longer occupied the position of the capital of the Roman Empire. During the period known as the tetrarchy, when four emperors ruled, none of them used Rome as their capital. Constantine’s father and Constantine himself ruled in Germany, on the Rhine frontier. The senior emperor in the West usually resided in Milan, in northern Italy. The senior emperor in the East was usually somewhere in Turkey; Diocletian’s capital was at Nicomedia. The junior emperor generally lived at Antioch in Syria. Major cities were chosen that were closer to frontiers and closer to the resources necessary to battle barbarians and suppress rebels.
A Map showing the division of the Roman Empire under the tetrarchy. (Image: Coppermine Photo Gallery/Public domain)
Learn more about a conservative emperor named Diocletian
A New Rome in Byzantium
Rome increasingly became a ceremonial capital. It was awkwardly placed. To this day, Rome really isn’t the capital of Italy, at least not in a financial or economic sense. Its importance is due to its political and religious significance. However, there was always a move to get the capital out of Rome to a better location.
Constantine, therefore, in many ways, was responding along the lines of what other soldier-emperors had done. Constantine made a major difference here. He decided to establish a capital, “New Rome,” which would be Christian in nature from the start. There would be no pagan gods. He chose the city of Byzantium, where we get the word “Byzantine”—Byzantine civilization.
