Who the hell thinks of Byzantium first when the term 'Greek Empire' is mentioned? I certainly don't, I think of of either classical Greece with Spatra, Athens and the Delian league etc., or big Al and his successors. Perhaps the question could be framed 'WI the Delian league defeated nascent Rome?', or 'WI one of Al's successors defeated the Romans?'. All this talk of what Byzantium was and wasn't isn't going anywhere useful, I certainly have learnt anything, other than people are argumentative about this.