The circle is where the byzantine empire was located is located.
Constantinople was called the new Rome because they basically had the same culture. Also Rome was obviously the capital of the Roman Empire, and Constantinople was the capital of The Byzantine Empire.
The Bosporus strait was the river body that made the byzantine empire a peninsula. It was important to the empire because it made it wealthier from taxing passing boats, and it helped to protect the empire from invaders.
Silk, woven cloth, fish goods. But they got really wealthy due to boats coming in through the bosporus strait. They would be trade boats, and the empire wouldn't let them pass unless they paid a tax.
Constantine, and Justinian. Justian/wife eliminated prostitution and they also built a lot of churches around the empire. He also built the hagia sophia. Constantine was responsible for the birth of the empire he was the one who made it. Constantine the great built walls around the capital constantine.
Emperor Justinian was most definitely not popular. He made higher taxes. They were so high that the whole of the Byzantine people wanted to overthrow him. They got slaughtered by their emperor. He was most definitely not popular to the common people. Contantine was popular because in order for the empire to be made he must have had some followers.