Rome Moved?

Why as a young student working my way through k-12 did I never learn of how Constantinople actually became the new capital of Rome? So much emphasis is put on the collapse of the Roman Empire, but little is actually taught regarding how and what happened. I was very interested to learn that not only did Constantinople become the new capital, but in fact flourished for the most part and controlled the east in the fourth and fifth centuries. I believe the perception is that the city of Rome is for many the face of the empire, so when it is repeatedly sacked in the 5 century we automatically think the collapse of the empire.
It was also interesting to read about Gaul (southern France), and how after the Franks invaded the Roman culture and lifestyle that once reined supreme did little but fade away. A new culture and identity was formed here with the cohabitation of both the empire citizens and the barbarians. It is crazy to think that what would come out of this relationship would as Dr. Knox said form what is essentially Europe. And after thinking about this situation it makes perfect sense to think that Europe came about by mixing both Roman Empire citizens and barbarians. It was as if they were refined only to a point, but also barbaric only to a point.