What is now called Asian Istanbul was probably inhabited by people as early as 3000 BC. Eventually, in the 7th century, Greek colonists led by King Byzas established the colony of Byzantium, the Greek name for a city on the Bosphorus. Byzas chose the spot after consulting an oracle of Delphi who told him to settle across from the "land of the blind ones." Indeed, Byzas concluded, earlier settlers must have been deprived of their sight to have overlooked this superb location at the mouth of the Bosphorus strait. This proved an auspicious decision by Byzas, as history has shown Istanbul's location important far beyond what these early Greek settlers might possibly have conceived. Byzas gave his name to the city: Byzantium.
In the early 100's BC, it became part of the Roman Empire and in 306 AD, Emperor Constantine the Great made Byzantium capital of the entire Roman Empire. From that point on, the city was known as Constantinople.
The mid 400's AD was a time of enormous upheaval in the empire. Barbarians conquered the western Roman Empire while the Eastern, also called the Byzantine Empire, kept Constantinople as its capital. In 532 during the reign of Justinian I, antigovernment riots destroyed the city. It was rebuilt, and outstanding structures such as Hagia Sophia stand as monuments to the heights Byzantine culture reached.
The attribute that made the city so desirable, its incomparable location for trade and transport between three continents, was also its nemesis. For the next several hundred years Persians, Arabs, nomadic peoples, and members of the Fourth Crusade (who for a time governed the city) attacked Constantinople.
Finally, weakened by almost constant battle, the Ottoman Turks lead by Fatih Sultan Mehmet II conquered Constantinople in 1453. Renamed Istanbul, it became the third and last capital of the Ottoman Empire. It was the nerve center for military campaigns that were to enlarge the Ottoman Empire dramatically. By the mid 1500's, Istanbul, with a population of almost half a million, was a major cultural, political, and commercial center. Ottoman rule continued until it was defeated in WWI and Istanbul was occupied by the allies.
When the Republic of Turkey was born in 1923 after the War of Independence, Kemal Ataturk moved the capital to the city of Ankara. But Istanbul has continued to expand dramatically; today its population is approximately 13 million and increases at an estimated 700,000 immigrants per year. Industry has expanded even as tourism has grown. It continues to be a city that creates its own history at the intersection where both Continents meet.
Aya Sofya (Haghia Sophia) Museum
The ancient Byzantine church, built by Justinian I between 532-537 AD after the Nika Riot, was later converted to a mosque with the addition of minarets in mid-15th century. The remarkable structure with its 56m high immense dome is a museum today in which you can see both Christian and Islamic art. There are good examples of the Byzantine mosaics as well. For about 1000 years this was the largest church in the world, and glory of the Byzantine Empire.
Yerebatan Sarayi (Cistern Basilica)
Byzantine cistern from the 6th century built by Justinian I and is located to the south-west of Hagia Sophia. The water was brought from Belgrade Forest, 19 kilometers to the north of Istanbul, and it had a capacity to store 100.000 tons of water. It features fine brick vaulting supported by 336 various type of columns brought here from different parts of the Empire. The Basilica Cistern, or Underground (Yerebatan) Cistern as locals call it, now houses a cafeteria and hosts musical and theatrical performances and a Biannual. There are also two Medusa friezes brought from the Temple of Apollo in Didyma (today's Didim).
Sultanahmet Square (Hippodrome)
Scene of horse and chariot races and the center of Byzantine civic life. It was the place where the Nik Riot started in 532 AD. There are an Egyptian Obelisk, a stone obelisk and the Serpentine Column which were originally brought by the emperors and used for the decoration of the Hippodrome. At the other side of the Hippodrome the German Fountains still functions today. The imperial lodge was located to the west of the Hippodrome where Ibrahim Pasha Palace stands now. Today Sultanahmet Square is a nice area for picnics and meetings.
Kapalicarsi (Grand Bazaar)
Built in the 15th century as a complex of 3,000 shops selling raw materials to be used in clothes manufacturing, the Covered Bazaar fulfills a viable commercial function to this day. The Bazaar's fine shops and exotic atmosphere, mingling the ancient and new, make it a "must-see" in Istanbul. It's divided into many sections such as leather, rugs, souvenirs, copper, antiques, textile etc. There are 18 gates and 60 streets inside.
Misir Carsisi (The Egyptian Spice Bazaar)
Built in the 17th century next to the Golden Horn, the Spice Bazaar is the second largest covered bazaar in Istanbul. Originally housing shops selling medicine and spices, the Spice Bazaar continues to fulfill its original function. This distinguished example of Ottoman architecture continues to sparkle with life even today.
Topkapi was the first Ottoman palace to be built (1466-1478) in the newly conquered capital of the Empire by Fatih Sultan Mehmet II. Located on the spot where the foundations of the city were first laid in ancient times by Megarian Chief Byzas in the 7th century BC, the palace boasts one of the most beautiful views of Istanbul, incorporating the Bosphorus, the Golden Horn, the two shores and the sea of Marmara. Unlike the European palaces, Topkapi is not a single monumental structure but a more organic complex made up of various kiosks, gardens and areas spread over the tip of the historical peninsula at the entry of the Golden Horn. Topkapi Palace served as the residence of Ottoman sultans for about 400 years, until Abdulmecid built the Dolmabahce Palace. In its hey-days, there were between 8-10 thousand people living in the palace, mostly being the Janissaries.
It was turned into a museum in 1924 and has become one of the most attractive palace-museums in the world. The most attractive exhibition halls of the palace are: treasury, Islamic, holly relics, costumes of the sultans, divan, harem, kitchens, Chinese porcelains and several kiosks such as the Baghdad, Revan, Sofa and Mecidiye.