Rough Roman Memes

Explanation: Later in the Roman Empire's existence, the center of political power moved away from Rome itself - and, subsequently, even the formal institutions of imperial power. Byzantium/Constantinople/Istanbul is the best known, but Ravenna in Italy and the travelling courts of the Emperors are also notable in this.

There was a strange and unique strength in treating a continents-spanning empire like the extension of a single city-state, both culturally and structurally - something that was lost with the increasingly dynastic and elite-cosmopolitan rule of the Late Empire.