The acropolis of the city named Byzantion was located in the area where today the Topkapi Palace stands. Today its agora coincides with present day Ayasofya. A hippodrome was built in the yaer 196 on some flat land terracing down to the Marmara Sea , which was later known as At Meydani (Square of the Horses). The city walls were passing just outside the palace. During the reign of Constantinus I, when significant construction activities were undertaken in the city, the old city walls were brought down and new ones were built which bounded a larger area. The city which continued its growth in subsequent years eventually spilled out of these walls. This led Emperor Theodosius II to build part of the city walls of Istanbul which have lasted up to present times.

The first bridge on the Golden Horn was built by Justinien, a connection between Ayvansaray - Kasimpasa to make Skyai easily accessible. Galata was given to the administration of the Genovese in 13 th century and sustained its commercial significance for centuries. In the 5th century, the city was one of the major cities of the world, with its population reaching 100 thousand. When 14 th century was reached, Constantinopolis was the administrative center of an empire whose boundaries had shrunk considerably and whose inhabitants were mostly involved with agriculture. Its population, which was around 50 thousand when conquered by the Ottomans, became more than 100 thousand when the Muslim and non - Muslim groups removed from Anatolia and Thrace and beyond (Rumeli) During this period, the majority of the Muslim population was living outside the peninsula were the old city was located. During the Ottoman period the population of the city grew even further, and the city also expanded physically. Skyai also bursted from the city walls and grew towards the Pera area (currently Galatasaray)

In the 19th century, significant developments were seen in Galata. While this section of the city preserved its importance as a commercial center, it started to achieve the characteristics of a European city, as foreign embassies, foreign banks, and foreign insurance firms and commissioners concentrated here and recreational facilities started to increase in number. The move of Ottoman Sultans from Topkapi Palace to the Dolmabahçe palace near Galata also took place in this century. Later, other palaces were built both in this area and on the shores of the Bosphorous. New settlement areas were also established around Kadiköy and Üsküdar.

Feshane, (the fez factory) which was the first significant industrial establishment of its times, was commissioned in the Golden Horn area. In the 19th century, the city had new means of transportation such as railways, trams, and a mini - metro, (the tunnel) both at the urban and intra - urban scale. While the port was being modernized, ferry operations were started along the Bosphorous. Railway connections were made to Izmit and Edirne , and suburban lines were being provided to connect the city to its immediate surroundings. The bridges connecting the two shores of the Golden Horn were also built in this century. In 1854, the Municipality of Istanbul was established.

Istanbul also has the honour of being the cradle of the innovative mode of urban transportation called "dolmus" (shared taxi) Turkey which is also seen in other cities of Turkey and some cities of the world.