The Incredible John said
The Byzatine empire (the Eastern Roman(Not really xroman) empire) also outlasted Rome itself.
The Byzantines were only called 'Byzantines' by the Holy Roman Empire. The Byzantines thought of themselves as Roman, as far as I know.
Edit: By the way, post is up.
Edit 2: And apparently, the name Istanbul comes from the Turks misunderstanding what the Romans were saying when they were asked where they were going. The Roman response was 'eis ten polin', or "into THE city"