So what was the same between them, and then what changed over time? So let's just do a review. This is what things look like at around the year 400. As you can see from an administrative point of view, even though it was considered one empire, it was already being governed separately, the West being governed from Rome, the East being governed from Constantinople. And most historians mark the beginning of the Byzantine Empire with the rule of Constantine, who moves the capital to Byzantium. It gets renamed Constantinople. But as we've talked about in multiple videos, in 476, you have the fall of the Western Roman Empire, and the West becomes fragmented, a bunch of various Germanic kingdoms, but the Eastern Roman Empire, with its capital at Constantinople, continues.