This made Rome very uncomfortable as an Imperial residence. Constantine(who ruled from 323 to 337) looked for a new capital. He chose Byzantium, the gate-way for the commerce between Europe and Asia. The city was renamed Constantinople, and the court moved eastward. When Constantine died, his two sons, for the sake of a more efficient administration, divided the Empire between them. The elder lived in Rome and ruled in the west. The younger stayed in Constantinople and was master of the east.
这样的事情常常发生，使得作为帝国首都的罗马变成了一个令人不快的居所。康士坦丁皇帝（公元23至337年在位）开始寻找一个新首都。他选择了位于欧亚之间的通商门户拜占庭，将其重新命名为君士坦丁堡，把皇宫迁到这里。康士坦丁死后，为更有效率地管理，他的两个儿子便将罗马帝国一分为二。哥哥住在罗马，统治帝国的西部；弟弟留在君士坦丁堡，成为东罗马的主人。
Then came the fourth century and the terrible visitation of the Huns, those mysterious Asiatic horsemen who for more than two centuries maintained themselves in Northern Europe and continued their career of bloodshed until they were defeated near Chalonssur-Marne in France in the year 451. As soon as the Huns had reached the Danube they had begun to press hard upon the Goths. The Goths, in order to save themselves, were thereupon obliged to invade Rome. The Emperor Valens tried to stop them, but was killed near Adrianople in the year 378. Twenty-two years later, under their king, Alaric, these same West Goths marched westward and attacked Rome. They did not plunder, and destroyed only a few palaces. Next came the Vandals, and showed less respect for the venerable traditions of the city. Then the Burgundians. Then the East Goths. Then the Alemanni. Then the Franks. There was no end to the invasions. Rome at last was at the mercy of every ambitious highway robber who could gather a few followers.
接下来到了公元4世纪，可怕的匈奴人造访欧洲。这些神秘的亚洲骑兵在欧洲北部整整驰骋了两个世纪，以杀人流血为职业，祸患四方，直到公元 451年在法国沙隆的马恩河被彻底击败为止。当匈奴人进军到多瑙河附近，对当地定居的哥特人产生了极大的威胁。为了生存，哥特人被迫侵人罗马境内。瓦伦斯皇帝试图抵御哥特人，在公元378年战死于亚特里亚堡。22年后，同一群西哥特人在国王阿拉里克的率领下，向西挺进，袭击了罗马。他们没有大肆劫掠，只是毁坏了几座宫殿。接着来犯的是汪达尔人，他们对这座具有悠久历史传统的城市缺乏敬意，纵火抢劫，造成极大的破坏。接下来是勃艮弟人，然后东哥特人，阿拉曼尼人，法兰克人……，侵略没完没了。罗马最终变成了任何野心家都唾手可得的猎物，只要他能召集一批追随的亡命之徒。