in Europe, in 2020 it was the 8th most densely populated country. The current largest metropolitan areas are listen below: Urbanisation Rapid urbanisation began with the onset of the Industrial Revolution in the mid to late 18th century, shifting jobs and more importantly people away from rural Britain's dominance at the time which was primarily agricultural, to manufacturing jobs within urban areas which started to spring up. In 1750, an estimated total of around only 1 million people lived in some sort of urban area such as a town or city, which was around 1/6th of the estimated total population but a century later this had risen to 8 million people in 1850, equating to just over half of the nation. While this mass urbanisation affected pre-existing cities to a large degree such as London, smaller and 'newer' towns were in particular effected by the re-distribution of the population and exploded in raw population growth. Cities such as Birmingham, Bristol, Edinburgh, Glasgow, Liverpool, Manchester, Leeds, Sheffield and Newcastle for example had an explosive expansion in population numbers around the middle of the 19th century due to the industrial expansion of said cities bringing jobs and again people in for work. London during the 19th century become noted as the 'premier city' of the world, being the most populated city from 1825 to 1900 and being the first city in Europe and one of the first in the world to reach the figure of one million inhabitants, and then 5 million inhabitants. This urbanisation in the 19th century has had two phases. David Herbert describes the process of the late 19th century and the early 20th century as a "maker and breaker" of the cities in the United Kingdom. This mass influx of the population into the cities resulted in a centralisation of the population into the inner city areas however by the time of the late 19th century and early 20th century when technological advancements in transport kicked off allowing cities to expand their 'peripherals' from the inner areas to create large scale 'city regions' of their own. London in particular, is a great example of this in effect, during the 19th century, the majority of people within the city lived in the inner part, however by the 20th century a massive expansion of 'Outer London' began which slowly became larger in population size by the middle of the century