Question

Why is the period of about two centuries from early fourth

century AD known as the Imperal Age?.​

Answer 1

The 4th century (per the Julian calendar and Anno Domini/Common era) was the time period which lasted from 301 to 400. In the West, the early part of the century was shaped by Constantine the Great, who became the first Roman emperor to adopt Christianity. Gaining sole reign of the empire, he is also noted for re-establishing a single imperial capital, choosing the site of ancient Byzantium in 330 (over the current capitals, which had effectively been changed by Diocletian's reforms to Milan in the West, and Nicomedeia in the East) to build the city soon called Nova Roma (New Rome); it was later renamed Constantinople in his honor.