Constantinople was named the new Rome because Rome got destroyed, and Byzantium was considered the new Roman Empire.
The Bospuras Strait is a body of water that combines the Black sea and the Sea of Marma. It was important because the Byzantines would charge ships to pass through, and it also allowed them to be a center of the trade.
One of the many reasons, Byzantium was so rich was because they were the center of trade, and some things that they traded were oils, and silks
Justinian was one of the best Byzantine Emperors. One thing that he accomplished, was that he extended the Byzantium empire, to parts of the old Western Roman Empire.
Emperor Constantine was also one of the greatest rulers of the Byzantine Empire. One thing that he accomplished was that he split the Roman Epire into the eastern and the western, creating Byzantium.
Yes there was a popular leader, because Constantine the great was popular.