Both "Western Roman Empire" and "Eastern Roman Empire" (or "Byzantine Empire") are modern terms describing de facto independent entities; however, at no point did Romans consider the Empire split into two, but rather considered it a single state governed by two separate Imperial courts out of administrative expediency.
Well... I read some posts where I found that the empire was officially split at a point.. I think I'll search more info tomorrow
they're probably referring to the final time there were two emperors (the roman empire actually did this many times) and the west fell less than 100 years later during the migration period.
