But that didn't make a different entity. Sure the Principate differed from the Dominate, but it was all continuously the Roman Empire. At the time the Western p

But that didn't make a different entity. Sure the Principate differed from the Dominate, but it was all continuously the Roman Empire. At the time the Western portion of the Empire fell it was legally controlled by two emperors in two capitals. The Eastern capital and emperor persisted. There's really nothing more to discuss. The US Constitution has also undergone a number of changes since the founding, and society is very different than it was 300 years ago, yet it would be absurd to say it's not the same entity. Internal changes are just that: internal changes. The Empire itself never fell until 1453.