Birmingham is a major city and metropolitan borough of West Midlands, England. It is the largest and most populous British city outside London, with a population in 2014 of 1,101,360. The city is in the West Midlands Built-up Area, the third most populous urban area in the United Kingdom, with a population of 2,440,986 at the 2011 census. Birmingham's metropolitan area is the second most populous in the UK with a population of 3.8 million. This also makes Birmingham the 9th most populous metropolitan area in Europe.A medium-sized market town in 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. Perhaps the most important invention in British history, the industrial steam engine, was invented in Birmingham. 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. From the summer of 1940 to the spring of 1943, Birmingham was bombed heavily by the German Luftwaffe in what is known as the Birmingham Blitz. The damage done to the city's infrastructure, in addition to a deliberate policy of demolition and new building by planners, led to extensive demolition and redevelopment in subsequent decades.