Karachi is the capital of the Pakistani province of Sindh. It is the most populous city in Pakistan, and fourth-most-populous city proper in the world. Ranked as a beta world city, the city is Pakistan's premier industrial and financial centre. Karachi is also Pakistan's most cosmopolitan city. Situated on the Arabian Sea, Karachi serves as a transport hub, and is home to 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 the fortified village of Kolachi in 1729. The settlement drastically increased in importance with the arrival of British East India company in the mid 19th century, who not only embarked on major works to transform the city into a major seaport, but also connected it with their extensive 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. Following the independence of Pakistan, the city's population increased dramatically with the arrival of hundreds of thousands of Muslim refugees from India.