Birmingham is the second-most populous city in the United Kingdom, after London, and the most populous city in the English Midlands. With an estimated population of 1,137,100 as of 2017, Birmingham is the cultural, social, financial and commercial centre of the Midlands. It is the main centre of the West Midlands conurbation, which is the third most populated urban area in the United Kingdom. The wider Birmingham metropolitan area is the second largest in the United Kingdom with a population of over 3.7 million. Birmingham is frequently referred to as the United Kingdom's "second city".