A visit to Istanbul, formerly called Constantinople, presents a very different city from the one found on this spot in the fourth century CE, when Roman Emperor Constantine renamed his Eastern capital after himself. The city was once called Byzantium by the Greeks. It was here that Constantine set the stage for the embrace of Christianity by emperors that came after him. Constantinople served as the seat of power for the Byzantine Empire for the next thousand years.
The best movie about the trials of introducing Christianity as the official religion of the Empire is Agora (2009), set in Alexandria, Egypt. At the end of the fourth century, the city was a hotbed of religious contention. Pagan worshipers were under extreme duress from newly empowered Christians, and the beautiful philosopher Hypatia (say High-patia as in patience) became a martyr in consequence of her Greek-inspired skeptical thinking. Greek philosophy was considered paganism by the Christians. In these years, Roman control of the empire shifted from the West to the new capital at Constantinople. Egypt was lost to the Muslim conquest in the year 641.
The most colorful and justly famous figure in the early centuries of the Byzantine Empire was Justinian I, who ruled from Constantinople in the years 527 to 565. The Emperor and his scandalous wife can be seen in Theodora, Slave Empress (1954). Further obstacles for Justinian are on view in Sword of the Conqueror (1961), set in Europe of 566. The Emperor is uneasy about the activities of pagan tribes in Europe to his West and sends emissaries to sow discord among them. Though he sits at the high end of Western Civilization in this time, he knows that beneath the palaces and cathedrals there is a seething magma of brutality, resentment, and vengeance. He exploits the situation by turning the barbarians against themselves.
There is a Turkish movie called Fetih 1453 (2012), or The Conquest 1453, about the capture of Constantinople by the Islamic Ottoman Turks in 1453. It has not been available in English, but the opening graphics (see trailer) show the city as it might have looked after a thousand years of Byzantine rule. Commanding the scene is the Hagia Sophia (say High-ya), built by Emperor Justinian I in the sixth century on top of earlier versions of the Eastern Orthodox cathedral. In reality, this is a romanticized view of the city. It never fully recovered it’s magnificence after being sacked by the Crusaders in 1204.