When the Western Roman Empire collapsed in the 5th century CE, Constantinople—known to the outside world as Rum—stood alone as the last bastion of Roman greatness. The fall of Rome to barbarian invasions in 476 CE shifted the balance of power eastward, leaving Constantinople as the sole heir of imperial majesty. For centuries, the city would serve as the capital of the Byzantine Empire, a realm both Roman and Greek, Christian and imperial. But the Middle ages were not kind to empires, and Rum would face