How Did Constantinople Become Istanbul?

In his 1915 travelogue, "Constantinople and Istanbul Old and New," H.G. Dwight writes, "Constantinople is a compromise, therefore, and not always a successful one, between north and south." In this instance, Dwight speaks of the jarring weather in the city, which blends the climate of regions to the north and south.

Yet, his statement also serves as an apt representation of the history of Constantinople (presently known as Istanbul), which is a city that stands as a centuries-long compromise — a melting pot — of peoples, religions and cultures.

From the Greeks to the Romans

Way back in the time before the common era (C.E.), Constantinople was the ancient capital of the Byzantine empire, though it was known at the time as Byzantium. Byzas the Megarian gave the region its name in 700 B.C.E., and a small settlement of Greeks lived there until 300 B.C.E.

In 330 C.E., Roman emperor Constantine I declared Byzantium to be the 'New Rome.' The settlement transformed into the major center of Constantinople, named after its new Roman conqueror. The ancient Byzantium thrived under Roman rule for more than 1,000 years, even as other parts of the Roman Empire collapsed.

"Constantinople was the capital of the Eastern Roman Empire. It moved from Rome in the 4th-5th centuries of the Common Era (C.E.). That was the formal foundation of the city [under] Emperor Constantine," says Cornell Fleischer. Fleischer is the Kanunî Süleyman professor of Ottoman and modern Turkish studies in Near Eastern languages and civilizations at The University of Chicago.

According to Fleischer, Venetian rulers attempted to conquer the city through a Christian crusade, and were briefly successful, ruling over the area from 1204-1260 C.E. But, otherwise, the empire remained in the hands of the Romans, serving as the empire's central seat of power until the Ottoman conquest in 1453.

The Ottoman Conquest

But how did Constantinople fall into the hands of the Ottoman Empire? According to Fleischer, the Ottoman "polity" was one of many principalities in the Balkans and northwestern Anatolia (also known as Asia Minor, in what is modern-day Turkey).

"The Ottoman principality was the one that was the closest — the closest in a number of senses — to Constantinople, to the center of empire. And conquest of the city had been a dream of sorts for a very long time," says Fleischer. "Indeed, there are traditions of the Prophet Muhammad that referred to the conquest of the city — the conquest of Rome — as one of the events that will usher in the culmination of the end of history or the end of times, whatever that might be."

There had been numerous attempted sieges of Constantinople starting in the late 1300s, but none had succeeded. But, finally, Sultan Mehmed II toppled the city after a 55-day siege. His army bombarded the city's defenses by both land and sea until the seat of the Byzantine Empire crumbled May 29, 1453.

Beyond Constantinople, the Ottomans had been steadily expanding their empire for decades, becoming a major world player in the process. "And the Ottomans had been pressing for several decades, and they had taken imperial territories in what had been the Balkans in particular — former Yugoslavia, Bulgaria, Greece. These areas were the cradle of what became the Ottoman empire."

Recent docudramas, such as "Rise of the Empires: Ottoman" on Netflix, have popularized this period of conquest for modern audiences.

Remaking the City

The Byzantine Empire had been in severe decline at the time of its conquest in 1453. Even though Constantinople was one of the largest cities in the world, its population had seriously dwindled, according to Fleischer. Fleischer says that census records from the time determine Constantinople's population to have been 30,000 people shortly after the conquest.

"After the conquest, repopulation and reconstructions were major priorities," says Fleischer. The population eventually rebounded to 400,000-500,000 people by the next century, he says.

One of the great rulers of Constantinople was Suleiman 'the Magnificent,' also commonly known as Suleiman 'the Lawgiver.' Suleiman's forefathers had done most of the heavy lifting of reconstructing Constantinople by ordering the creation of mosques, universities and hospitals.

"What Suleiman did was ... to build in a very distinctive architectural style imperial monuments in the form of mosques and schools and so forth throughout the territories [of the empire]," says Fleischer.

One of the mosques that Suleiman commissioned, was the Süleymaniye Mosque. Constructed by architect Mimar Sinan in the 1550s, the imperial mosque became a significant religious and educational center. The mosque still stands in Istanbul today as the one must-see relics from the Ottoman Empire.

A Cultural, Religious and Commercial Hub

There is no specific date for when, exactly, Constantinople became the capital of the Ottoman Empire. There had been several centers of power in the Ottoman Empire, including Bursa, which became the "intellectual and spiritual capital of the enterprise by the 15th century," according to Fleischer. But, he says, "with the conquest of Constantinople and its reconstruction and the construction of imperial mosques and universities, the center, by the middle of the 16th century, really moved to Constantinople."

Due to its significant geographic location at the crux of Europe and Asia, surrounded by both land and sea, Constantinople was well-positioned as not only a center of cultural and religious activity, but also as a commercial center.

Constantinople formed a hub, or "expanded network of trade routes," says Fleischer. "And the trade routes were augmented by the construction of caravanserai, which were structures for long-distance traders, all the way from Iran to the borders of what is now known as Austria."

Most notably, under the Ottoman Empire, a variety of religions and languages flourished, from Greek-speaking Orthodox Christians to Turkish-speaking Muslims. "The Ottomans weren't trying to convert everybody to Islam," says Fleischer. They saw themselves and presented themselves as protectors of all of the monotheistic religions of the world — meaning the Christians, the Jews, as well as the Muslims."

Süleymaniye Mosque — A crescent moon shines in the sky over Suleymaniye Mosque in Istanbul, Turkey, on August 23, 2020.
Isa Terli/Anadolu Agency/Getty Images

As a result, Constantinople remained a majority non-Muslim area well into the 16th century. Instead of wholly dismantling pre-existing religious artifacts, the Ottoman Empire maintained them, retaining their architectural structures — such as large columns — even when converting them into churches and synagogues.

"The large symbolic churches were converted into mosques. This was normal practice, particularly in the 15th and 16th centuries, with the architecture being preserved, but modifications being made to allow for proper orientation for the direction of prayer and so on," says Fleischer.

Overall, the Ottoman rule favored multiculturalism. "In the Ottoman case, their policy of rule was based on inclusivity and capacity to maintain and tolerate a great deal of diversity," according to Fleischer.

Modern Istanbul Is a Multi-cultural City

Despite the changing of hands from the Byzantine to the Ottoman Empire, 'Constantinople' stayed in place as the formal name of the city until the early 20th century, when the last shreds of the Ottoman Empire crumbled and the Republic of Turkey began.

"The terminology of Constantinople in Arabic (Konstantiniye) was preserved. That was the official name of the place until the early 20th century when the empire was ended by the advent of the Republic," says Fleischer.

After that point, the city became more formally known by the name 'Istanbul,' which derives from the Greek phrase, "Stanbulin," meaning "to the city." However, residents of the city had colloquially referred to the city as Istanbul for many years before the official name change, switching between Istanbul and Constantinople depending on the situation. Many residents called the old part of the city 'Stamboul' well into the 19th century.

The city continues to appeal to tourists for its multi-cultural heritage and profusion of different religious architectural sites. However, the current government under Prime Minister Recep Tayyip Erdoğan has favored a country largely intended for Turkish, Sunni Muslims, according to Fleischer.

The end result has "meant that the so-called minority populations, particularly the Christians and Jews, have shrunk substantially through emigration," says Fleischer. "I'm not sure that many people who live in greater metropolitan Istanbul today would recognize that Constantinople was the name of the place until sometime nearly within the reach of living memory."

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