Birmingham is a city and metropolitan borough in the West Midlands of England, United Kingdom. It is the most populous British city outside London with 1,092,330 residents (2013 est.), and its population increase of 88,400 residents between the 2001 and 2011 censuses was greater than that of any other British local authority. The city lies within the West Midlands Built-up Area, the third most populous built-up area in the United Kingdom with 2,440,986 residents (2011 census), and its metropolitan area is the United Kingdom's second most populous with 3,701,107 residents (2012 est.).A medium-sized market town during the medieval period, Birmingham grew to international prominence in the 18th century at the heart of the Midlands Enlightenment and subsequent Industrial Revolution, which saw the town at the forefront of worldwide advances in science, technology and economic development, producing a series of innovations that laid many of the foundations of modern industrial society. By 1791 it was being hailed as "the first manufacturing town in the world". Birmingham's distinctive economic profile, with thousands of small workshops practising a wide variety of specialised and highly skilled trades, encouraged exceptional levels of creativity and innovation and provided a diverse and resilient economic base for industrial prosperity that was to last into the final quarter of the 20th century. Its resulting high level of social mobility also fostered a culture of broad-based political radicalism, that under leaders from Thomas Attwood to Joseph Chamberlain was to give it a political influence unparalleled in Britain outside London, and a pivotal role in the development of British democracy.