The Roman Empire was a true empire in that it comprised many very dissonant places and cultures under one umbrella. For the time, logistically, the scope was ab

The Roman Empire was a true empire in that it comprised many very dissonant places and cultures under one umbrella. For the time, logistically, the scope was absurd and power was very weak or yielded in many areas. It was bound to fail for this reason alone. There were kingdoms within who sometimes battled Rome, installed antipopes or just ignored Rome altogether. It was remarkably loose and the reason Germanic kingdoms were able to consolidate so (relatively) quickly was because they basically already operated as a German kingdom. The British Empire is a far better analog but on a shorter timeframe. American imperialism was curbed early on and assimilation was done largely by force. Beyond that it grew at a time of great communication improvements and radical methods for building nationalism via mass communication.