Final answer:
Constantine moved the capital of the Roman Empire to Constantinople in 330 CE, marking the beginning of the Byzantine Empire's prominence.
Step-by-step explanation:
During his reign, Emperor Constantine moved the capital of the Roman Empire from Rome to the newly founded city of Constantinople (modern-day Istanbul) following the consolidation of his power after defeating his co-emperor Licinius in 324 CE. He officially dedicated Constantinople as the new capital in the year 330 CE, transforming the ancient Greek city of Byzantium into a new center for trade, administration, and Christian culture. This strategic move helped to define the future of the empire, with the Eastern Roman Empire thriving as Byzantium, while the Western Roman Empire eventually declined.
Constantine's action led to the city of Rome's reduction in prominence and paved the way for the eventual rise of the Byzantine Empire, characterized by its own unique artistic and cultural achievements. The Byzantine Empire outlasted the fall of the Western Roman Empire by roughly a thousand years, emphasizing the lasting impact of Constantine’s strategic decision to relocate the capital.