When did the Roman Empire fall (your thoughts)?

[starman2012]

But "Rome" was a constantly evolving concept. How does one define it? How much would the Romans under the kings have in common with Scipio, Cicero, Antoninus Pius or Diocletian? Could these diverse people even agree upon a common ideal or goal for the Roman res publica?

Just a desire to serve the Roman State. That's one thing most citizens had in common prior to the fifth century.