Why did Constantinople become the capital of Rome?

In 285 A.D., the emperor Diocletian divided the Roman Empire into east and west, each with its own capital. The western capital remained in Rome, while the eastern capital was established in Nicomedia.

In 330 A.D., Constantine I, the first Christian emperor, moved the eastern capital to Byzantium, which he renamed Constantinople. Constantinople remained the capital of the eastern Roman Empire, even after the western Roman Empire collapsed in the 5th century. The eastern Roman Empire continued to exist until 1453, when Constantinople was conquered by the Ottoman Turks.