Istanbul

Istanbul, historically also known as Constantinople and Byzantium, is the most populous city in Turkey and the country's economic, cultural, and historic center. Istanbul is a transcontinental city in Eurasia, straddling the Bosphorus strait between the Sea of Marmara and the Black Sea. Its commercial and historical center lies on the European side and about a third of its population lives on the Asian side. The city is the administrative center of the Istanbul Metropolitan Municipality (coterminous with Istanbul Province), both hosting a population of around 14 million residents. Istanbul is one of the world's most populous cities and ranks as world's 6th-largest city proper and the largest European city.

Founded under the name of Byzantium on the Sarayburnu promontory around 660 BCE, the city developed to become one of the most significant in history. After its reestablishment as Constantinople in 330 CE, it served as an imperial capital for almost 16 centuries, during the Roman and Byzantine (330–1204 and 1261–1453), the Latin (1204–1261), and the Ottoman (1453–1922) empires. It was instrumental in the advancement of Christianity during Roman and Byzantine times, before the Ottomans conquered the city in 1453 and transformed it into an Islamic stronghold and the seat of the Ottoman Caliphate.

Istanbul's strategic position on the historic Silk Road, rail networks to Europe and the Middle East, and the only sea route between the Black Sea and the Mediterranean have produced a cosmopolitan populace, although less so since the establishment of the Turkish Republic in 1923. Overlooked for the new capitalduring the interwar period, the city has since regained much of its prominence. The population of the city has increased tenfold since the 1950s, as migrants from across Anatolia have moved in and city limits have expanded to accommodate them. Arts, Music, Film and Cultural festivals were established at the end of the 20th century and continue to be hosted by the city today, and infrastructure improvements have produced a complex transportation network.

Approximately 12.56 million foreign visitors arrived in Istanbul in 2015, five years after it was named a European Capital of Culture, making the city the world's fifth most popular tourist destination. The city's biggest attraction is its historic center, partially listed as a UNESCO World Heritage Site, and its cultural and entertainment hub can be found across the city's natural harbor, the Golden Horn, in the Beyoğlu district. Considered a global city, Istanbul has one of the fastest-growing metropolitan economies in the world. It hosts the headquarters of many Turkish companies and media outlets and accounts for more than a quarter of the country's gross domestic product. Hoping to capitalize on its revitalization and rapid expansion, Istanbul bid for the Summer Olympics five times in twenty years. Istanbul will bid for 2023 Summer Youth Olympics.

Present-day Istanbul is a flourishing city, with a constantly growing skyline which is one of the most prominent in all of Europe and Western Asia. New developments are constantly being implemented including new metro lines, residential buildings and underground transportation projects such as the MarmarayTunnel which is the deepest underground tunnel in the world. Along with these developments, the city is increasingly becoming the centre of operations for many international organizations such as the Organization of the Black Sea Economic Cooperation, Turkic Council and D-8 Organization for Economic Cooperation.

Undercover
Bardem Aikan and his brother Demir were born in Istanbul to their mother and their father Farukh, who is not from Istanbul and is also the leader of the Aikan crime syndicate. By the events of Season 4, they appear to be living in a giant flourishing mansion in Beshiktash, the most wealthy and expensive neighbourhood of Istanbul.

Half of the storyline of the fourth season of Undercover takes place in Istanbul where exiled crime lord Petar Tudzharov allies himself with the Turkish mafia in an effort to restore their channels to Western Europe and also reclaim his power in Bulgaria, which ultimately fails, leaving Dzharo, Bardem and many of their men dead.