Istanbul is Turkey's most populous city and serves as its cultural and financial hub. Situated on both sides of the Bosphorus, the narrow strait between the Black Sea and the Sea of Marmara, Istanbul connects Asia and Europe both geographically and culturally. The city is known for its historical peninsula and numerous important sites, making it a unique location that has been the capital of several civilisations throughout history. Today, Istanbul remains a home for people from around the world.

Formerly known as Byzantium and Constantinople, Istanbul continues to be Turkey's economic, cultural, and historical centre. It is a transcontinental city, with its commercial and historical centre located on the European side of the Bosphorus. At the same time, about one-third of its population resides in the suburbs on the Asian side. As of 2024, Istanbul ranks as the world's fifth-largest city proper and remains the largest city in Europe.

Istanbul Population
Istanbul is the most populous city in Turkey and one of the largest cities in the world. As of the latest figures, Istanbul’s population is over 15 million people. The city's population has seen continuous growth over the years due to internal migration and its strong economic opportunities. This diverse population includes people from various cultural and ethnic backgrounds, contributing to Istanbul's vibrant and multicultural atmosphere.

Istanbul Metro Population
The metropolitan population of Istanbul extends beyond the central city limits and includes various surrounding districts. The wider Istanbul metropolitan area has a population of approximately 16 to 17 million people. This metro area encompasses a mix of residential, industrial, and commercial zones, reflecting Istanbul’s role as an economic, cultural, and social hub of Turkey. The high metro population density highlights the city's importance and its continued appeal to people seeking work, education, and better living conditions.

Istanbul Size
Istanbul covers an area of about 5,343 square kilometres, making it one of the largest cities in terms of land area in Europe and the Middle East. The city stretches across both the European and Asian continents, divided by the Bosporus Strait. Istanbul’s size contributes to its diverse neighbourhoods, each with distinct characteristics, from historic districts and bustling markets to modern business centres and suburban residential areas.

Where is Istanbul Located?
Istanbul is located in northwestern Turkey, straddling two continents: Europe and Asia. The city is uniquely positioned along the Bosporus Strait, which connects the Black Sea to the Sea of Marmara. The European part of Istanbul is where most of the historical and economic activities take place, while the Asian side features more residential and business districts. This strategic location has made Istanbul a critical point for trade and cultural exchange throughout its history.

• Istanbul was the capital city of three major empires: the Eastern Roman Empire, the Byzantine Empire, and the Ottoman Empire.
   
• In 330 AD, Roman Emperor Constantine the Great made the city the capital of the Eastern Roman Empire. He built it on seven hills, similar to Rome, and the city was named Constantinople ("City of Constantine"), previously known as Byzantium since 660 BC. The city was officially renamed Istanbul in 1930, though many still referred to it as Constantinople. The Turkish post office encouraged the use of the new name by not delivering mail addressed to Constantinople.
   
• Istanbul is located in north-western Turkey, within the Marmara Region, covering a total area of 5,343 square kilometres (2,063 square miles).
   
• Istanbul is the only city in the world that is geographically located in both Europe and Asia.
   
• As of 2024, Istanbul has three international airports: Istanbul Airport (on the European side), Sabiha Gökçen International Airport (on the Asian side), and a third airport that has recently been completed to further expand the city's air travel capacity.
   
• There are now three suspension bridges on the Bosphorus Strait that connect Europe and Asia. The third bridge, the Yavuz Sultan Selim Bridge, was completed in 2016.
   
• The Marmaray tunnel, which connects the rail system between Europe and Asia, was completed in 2013. The second tunnel, the Eurasia Tunnel, designed for motor vehicles, was opened in 2016 and is in full operation.
   
• Istanbul was the most populous city in the world in 1502, a title later taken by London in 1840.
   
• The Blue Mosque remains the only mosque in Istanbul with six minarets, the maximum number allowed for a mosque.
   
• Istanbul has the third-oldest subway in the world, built-in 1875. It is 573 meters long and located in the Tunel neighbourhood of the Beyoglu district. 
• The London subway was built in 1863, and the New York subway in 1868.
   
• Istanbul was the European Cultural Capital in 2010. By 2024, it continues to be one of the top tourist destinations globally, attracting millions of visitors every year. In 2023, Istanbul hosted over 16 million international tourists, making it one of the most visited cities worldwide.
   
• Istanbul remains a key candidate for hosting future Olympic Games, though it did not win the bid for the 2020 Summer Olympics.
   

Istanbul Province, is governed by the Istanbul Metropolitan Municipality (MMI), which oversees its 39 districts. This administrative framework traces its origins back to the Tanzimat reforms of the 19th century. Before these reforms, the city was governed by Islamic judges and imams under the supervision of the Grand Vizier. In line with the French model of city administration, the religious governance system was replaced with a mayor and a citywide council made up of representatives from the various religious groups in the city.

As of 2024, Istanbul continues to function under the governance of the MMI, with Ekrem ?mamo?lu serving as the city's mayor. The city's population has now exceeded 16 million, making it one of the largest cities in Europe. Istanbul faces various challenges related to rapid urbanisation, including transportation, housing, and environmental concerns, which remain key focus areas for city administration. The city's third airport, Istanbul Airport, completed in 2019, is now fully operational and one of the busiest in the world, contributing significantly to the city's global connectivity. Since 2004, Istanbul's municipal boundaries have aligned with the boundaries of its province. The city, regarded as the capital of 

 

Istanbul remains a key economic powerhouse for Turkey, contributing significantly to the nation's overall wealth. As of 2024, the city's gross domestic product (GDP) adjusted for purchasing power parity (PPP) is estimated to be around US$420 billion, placing it among the top 25 urban economies globally. Since the mid-1990s, Istanbul’s economy has continued to be one of the fastest-growing among OECD metro regions, reflecting its importance in Turkey's financial and industrial sectors.

Istanbul contributes approximately 30 percent to Turkey's overall GDP, a slight increase from previous years, with around 21 percent of the nation's industrial labour force based in the city. Its GDP per capita and productivity remain significantly higher than the national average, by about 65 percent and 55 percent respectively, owing to the focus on high-value-added sectors such as finance, technology, and services. The city is home to a thriving startup ecosystem, particularly in fintech, digital commerce, and technology innovation, attracting both domestic and international investments.

With its large population and economic activities, Istanbul is responsible for roughly 40 percent of the national tax revenue. This includes the wealth generated by 41 billionaires residing in the city, placing Istanbul in the top five cities globally in terms of the number of billionaires. The business districts of Levent and Maslak continue to be hubs for finance and commerce, with significant skyscrapers and business centres reshaping the city’s skyline.

Although Istanbul’s economy has diversified, traditional industries such as low-value-added manufacturing still account for a significant portion of its output. Manufacturing makes up around 24 percent of the city’s GDP, but it remains a vital component of Istanbul’s export market, contributing nearly 75 percent of the city’s total exports. By 2023, Istanbul-based companies had generated exports valued at US$82 billion and imports worth US$95 billion, accounting for 58 per cent and 62 percent of Turkey’s total exports and imports, respectively.

Today, Istanbul has benefited from Turkey’s growing economy, but this rapid expansion has created challenges, especially in building infrastructure to meet the needs of its residents while maintaining access to green spaces and essential resources like water.

Istanbul has focused on improving its transport links to manage this growth. The Yavuz Sultan Selim Bridge, Marmaray Tunnel, and Eurasia Tunnel all connect the European and Asian sides of the city across the Bosphorus Strait, helping to reduce traffic congestion.

Istanbul's third airport, named Istanbul Airport, opened in 2018. It is now one of the world’s largest airports, handling nearly 120 million passengers annually. Future expansion plans aim to increase this capacity to 200 million passengers.

The city continues to expand its metro and tram systems to improve public transport. New projects are also underway to address environmental concerns, including better waste management and the preservation of green spaces. While Istanbul has made significant progress in expanding its infrastructure, the challenge remains to balance growth with environmental sustainability.