"Istanbul was Constantinople. Now it's Istanbul, not Constantinople. Been a long time gone, Constantinople. Why did Constantinople get the works? That's nobody's business but the Turks" (first line of the song "Istanbul" by They Might be Giants) who's familiar with the old song "Istanbul (not Constantinople)"? It's a fact, though. Before it was called Istanbul, the city was once named Constantinople. Thousand years ago, the City of Constantinople was a very important city which was the center of trade and cultural diffusion and it was known as the capital of the Byzantine Empire. It was used as the capital of the Roman Empire before it fell, but after the Empire knocked down, it was the Byzantine's. Still, when Byzantine Empire has Constantinople, the city was the capital of the Empire and was a main point for traders from the Europe and Asia. Constantinople power never dies, it exists until now. Only that Constantinople was now modern day Istanbul and the government systems were changed into republic so Emperor no longer ruled.
As far as people learned about the Byzantine Empire, they'll mostly learn about Istanbul and its origin which was used to be named Constantinople. The name Constantinople was derived from the name of the conqueror of the Roman Empire, Constantine the Great. The reason why he did it is that because his empire was Christian and he himself, too. Constantine the Great was the first Christian emperor of Rome. His real name was Flavius Valerius Aurelius Constantinus. When he was the emperor of Rome, Seljuk- which is modern day Turkey had freedom to worship and Christian churches were legalized. Properties which were grabbed from the Christians were given back. From then on, the city that was called Byzantium was changed by the name Constantinople- Constantine changed it. Constantine was the first emperor who built the Cathedral in Constantinople and other part of Rome and Seljuk. Before Constantinople was the capital of the Roman Empire, Rome was the capital of the Empire. And then when Constantine was ruling the Roman Empire, but because of the strategic geographic place and the prosperity of the city, he moved the capital Rome to Byzantium and changed its name into Constantinople. The city really inculcated people eyes including the Roman Empire until he made it into the capital of the empire.
The city named Constantinople was the center of everything in that period. Because of its strategic geographic location, it was the intersection point that links between Asia and Europe. Along the city, there's a trade route called the Silk Road which was dessert everywhere and it was trader path to travel from East to West and from West to East. According to the geographic location, the city was between the Black Sea and the Mediterranean Sea. Because of this, Turkey rarely gets invaded. Talking more about geography, it was the most beautiful city that time and some rulers were lustful for conquering it. Religion is a good feature of the Byzantine Empire, because it has a very different system than any other European religions in the old time. There are many highlights in the Orthodox Religion. The Eastern Orthodox literally uses the Iconoclasm system or the system where they pray to images of Jesus and other saints. The Byzantine Empire was the only Empire who has the Orthodox Church, because there was a Great Schism in 1054 where the Eastern (Orthodox) Church excluded itself from the Western (Roman Catholic) Church. Unlike the Western Roman Catholic Church, the leader of the Orthodox Church was called Patriarch. In the end, Turkey was conquered by the Ottoman Empire and the Christian country was transformed into an Islamic country.
As it was discussed before, the city was located in a strategic location which makes it an ideal place for trading. People from Europe and Asia go there and by through this city for many years. The purpose of that is trading. Why in Constantinople? Because of its geographic location. The city was like the center of Europe and Asia. There people from China would bring Silks to be traded by European nobles and people from India would bring spices and gems to be traded too. The most famous trade between Europe and Asia was the Silk trades. They don't only trade with things, but cattle, too such as donkeys and hawks from Egypt and North Africa. In the 550s, Persia and India were mortal enemies. So, India monks persuaded Justinian by giving him the information for silk makings including the substances and how to make it. The purpose of this was that so Rome doesn't need to purchase silks from Persians. The silk was made from silkworms which when they hatch their eggs, the eggs were spin with the worms' own saliva which ends up a silk. In the Byzantine Age, before the Europeans have the silk industry from the India monks, silk was a very rare type of cloth which was popular in the Roman Empire. Roman nobles would be willing to buy silks from the Chinese with a very overwhelming price. So, silk was a very important material in that age and people would sell it with a very expensive price. Even today, they still do that even though Silk was already very common.
Not only trades were the main features of the Byzantine Empire, but cultural diffusion is the main reason why Constantinople was very special. After several times of Rome Golden Age, the Empire fell because of the schism. It was divided into the West part and the East part. The West part had the Western Roman Catholic Church which is now one of the main religions in the world. The Eastern part was the Eastern Orthodox Church which only exists in Russia nowadays. The cause of the great schism was the conflict between the church and the emperor. The Eastern Roman Emperor banned the worships of icon because it was against God's rule. Then, the patriarch didn't agree with it, so the patriarch excommunicated the emperor who results into the conflict of West and East. Not only was the religion part of the cultural diffusion, but the invasions, too. In 1453, the empire was invaded by a group of invaders from Central Asia called the Ottoman. The Ottoman ended up conquering the empire and spread Islam. Before the Ottoman arrived, the city was invaded by the Seljuk Turks, so the emperor called help from the Western Roman Empire. But then, it results to the first crusades, and during the crusades, trade rivalry appeared between the empire and Venice. So then, in the fourth crusades, merchants from Venice persuaded knights to destroy Constantinople. So, in that time the city was weakened that it leads to being conquered by the Ottomans. Cultural influences rather than from the Muslims were that they also were influenced by Greco- Roman architecture for Byzantine palaces and. Not only Greek and Romans style, but Middle Eastern, too. The cultural diffusion in Istanbul had a very long history and a very long way - longer than what people thought.
The Byzantine Empire had a very interesting history especially for the city. It inculcated people's sight. Its richness never fades until now. The history of this city tells us how many struggle it has been through especially in the crusades and the invasions, but it ended up as a great city nowadays. People admired its architectures. So, never underestimate the power of Istanbul because not everyone knows the origins and history of this amazing city.