The history of Istanbul, formerly known as Constantinople, dates back to 3000 BC when it was first inhabited by humans. In the 7th century BC, Greek colonists led by King Byzas established the area and named it after the old Greek name for a city on the Bosphorus coast, which is now called the "Old City of Istanbul."
During the early 100 BC, Byzantium became part of the Roman Empire, and in AD 306, Emperor Constantine the Great made it the capital of the Eastern Roman Empire. From that point, it was known as Constantinople.
Following the fall of the Western Roman Empire in AD 476, Constantinople remained as the capital of the Byzantine Empire until it was conquered by Muslims in 1453. The city suffered significant damage during Justinian I's reign (532-565) but was reestablished. Crusader armies sacked Constantinople again in 1204, destroying much of what was left.
Finally, weakened by invasions and battles, the Ottoman Turks led by Sultan Mehmet II were able to conquer Constantinople and rename it Istanbul, which became the third and last capital of the Ottoman Empire. Istanbul became a major cultural center for military campaigns during its time.
Today, Istanbul is one of the most populous cities in Europe, with a population of over 15 million people. In 1923, with the establishment of the new Republic of Turkey, Kemal Ataturk designated Ankara as the country's capital. Despite its tremendous growth and population, Istanbul continues to be a bustling city that harmoniously mixes Eastern and Western cultures.
For those interested in exploring Istanbul, there are many possible daily and private tours available, as well as numerous things to do, activities, and places to visit. A comprehensive list of these options can be found below.