Karachi (Urdu: کراچی; Sindhi: ڪراچي; ALA-LC: Karācī, IPA: [kəˈrɑːˌtʃi]) is the capital of Sindh, and is the largest and most populous city in Pakistan, as well as the 7th largest in the world and the world's second most populous city proper. Ranked as a beta world city, the city is Pakistan's premier industrial and financial centre. Karachi is also Pakistan's most cosmopolitan city. Located on the shores of the Arabian Sea, Karachi is a major transportation hub. The city is home to two of Pakistan's two largest seaports, the Port of Karachi and Port Bin Qasim, as well as the busiest airport in Pakistan.
Though the Karachi region has been inhabited for millennia, the city was founded as a village named Kolachi that was established as a fortified settlement in 1729. The settlement drastically increased in importance with the arrival of British colonialists who embarked on a major works to transform the city into a major seaport, and established connections to the extensive British Indian railway network. By the time of the Partition of British India, the city was the largest in Sindh with an estimated population of 400,000. Immediately following independence of Pakistan, the city's population increased dramatically with the arrival of hundreds of thousands of Muslim refugees from India. The city experienced rapid economic growth following independence, attracting migrants from throughout Pakistan and South Asia.
Karachi is now Pakistan's premier industrial and financial centre. The city has a formal economy estimated to be worth $113 billion as of 2014. Karachi collects over a third of Pakistan's tax revenue, and generates approximately 20% of Pakistan's GDP. Approximately 30% of Pakistani industrial output is from Karachi, while Karachi's ports handle approximately 95% of Pakistan's foreign trade. Approximately 90% of the multinational corporations operating in Pakistan are headquartered in Karachi. Up to 70% of Karachi's workforce is employed in the informal economy, which is typically not included in GDP calculations.
Karachi is one of Pakistan's most secular and socially liberal cities. It is also the most linguistically, ethnically, and religiously diverse city in Pakistan. No census has been conducted in Pakistan since 1998, but with an estimated population of between 15 and 23.5 million people in its greater metropolitan region, Karachi is considered to be the second-largest city in the Muslim world, and is the world's 7th most populous urban agglomeration. Karachi is considered to be one of the world's fastest growing cities, and has communities representing almost every ethnic group in Pakistan. Karachi is also home over 2 million Bangladeshi migrants, 1 million Afghans, and up to 400,000 Rohingyas from Myanmar.
Known as the "City of Lights" in the 1960s and 1970s for its vibrant nightlife, Karachi was beset by sharp ethnic, sectarian, and political conflict in the 1980s with the arrival of weaponry from the War in Afghanistan. The city had become well known for its high rates of violent crime, but recorded crimes sharply decreased following a controversial crackdown operation against criminals, the MQM political party, and Islamist militants initiated in 2013 by the Pakistan Rangers. The city's murder rate in 2015 had decreased by 75% compared to 2013, and kidnappings decreased by 90%, with the improved security environment triggering sharp increases in real-estate prices.