Constantinople and its walls during the Byzantine era

In the Roman period, the city was founded for the first time in A.D.195 by the Emperor Septimus Severus (193-211) and called Nea Roma or Antoninia. Istanbul was rebuilt by the Emperor Constantinus I, The Great (307-337) between the years of AD. 313-337 and named Constantinopolis after his name. Today, the city is called Istanbul.