There were both general and particular reasons why the eighteenth century was a century of urban growth and amoung the general reasons were the rise in national population, the expansion of industry and commerce, and the displacement of growing numbers of country-dwellers by an agricultural revolution.  At the beginning of the 18th century, Britain was primarily an agricultural country with most people living in rural areas and the majority of workers and industires operated within a domestic system. 2]
This involved people working in their own homes to produce goods and also to cultivate food on their own farm or piece of land. During the 18th centuy, there was a gradual move away from this way of working and the growth of urbanisation changed the domestic system to improve the lives of the British public. Urbanisation brough together all the manpower it required, whether for manual work or for the tertiary sector where the new age was creating more and more jobs, especially once London became more urbanised. 3]
A further indicator of the abundance of the labour supply was the enormous number of domestic servants and at the end of the 18th century, domestic servants made up over 15% of the population of London and ultimately, England had no labour shortage as it was being urbanised.  The invention of machines after the industrial revolution led to a transformation in the ways in which goods could be produced and the speed and scale of the process of the 18th century, saw significant changes in the size, location and lifestyle of the British population. 5] Industrialisation was a very important influence in stimulating the movement to urbanisation and the growth of factories and the availibility of work in them attracted people from rural areas and sustained higher densities of people in London. Industrialisation was a majour factor in the population growth and urbanisation in London in the 1700s and although it initially created a new urban poverty, the living standards of the working class rose from the mid-18th century onwards as new employment opportunities became vailable. 
During the 18th century, major improvements occurred whilst London was being urbanised, especially in agricultural prodoction. Modern scientific farming methods brought about new tools and farming machines, new methods, improved crops and employment rose.  In 1702, 1757, 1769 and 1773 Parliament passed legislation, liberalizing the economy and this led many to conclude that libralization significantly contributed to accelerate growth, due to urbanisation. 8] The vast majority of economic historians do not believe that any of these variables alone was responsible for the boom in the British economy, although many believe that urbanisation was essential for the Londons improvement in its economy beause it is frequently asserted that it was the concomitant effect of all of them that delivered the improved performance.  Farming was modernised through the use of enclosure, the enlargement of farms, the use of new methods, new crops and the population grew, commerce expanded, and London promoted exports. 10]
Due to urbanisation and the industrial revolution, the English countryside intergrated into the islands national market; as a component part of this network, English farms fed the population of the towns and industrial conurbations; they were the essential component in a domestic market which provided London to continue to develop in its early days.  It also had colonies, and London enjoyed the same stock of natural resources as it did a century later, all because of London becoming urbanised and it brought London into political stability as it also liberalised the economy. 12] Within the industrial revolution as a whole, Britian went through a series of individual revolutions once London became more urbanised and the British public revolutionised in its agriculture, demography, inland transport, technoloy, trade and industry. 
As Europes commetial and finantial centre of gravity shifted to London in the early 18th century, a strong territorial state and an intefrated national economy provided the resources for a new type of commercial metropolis, the modern world city.  Although urbanisation brought prosperity to London, the social consequences of urbanisation left a huge social upheaval in the 18th century which had a majour effect on the physical and social conditions in which people had to live. The consequences of a large mass of people moving to live around new factories in a relatively short space of time included housing shortages and squalor, sanitation problems, public health problems and regular utbreaks of disease and exploytation of workers and widespread poverty.  As the population increased in Britain, people moved from the countryside to the unrestrainedly frowing towns, which faced serious public health problems. The poor physical conditions in urban areas in the 18th century led to majour public health problems and rapidly growing cities experienced majour outbreaks of disease, epidemics and other problems of : overcrowded, damp, and poorly ventilated housing. 16]
Urbanisation also contributed to the lack of an effective sewerage system, industrial pollution, the lack of a clean water supply and a lack of undertanding about how infectious diseases were spread and so, many people living in the 18th century died at a relatively young age of infectious diseases that were contracted because of the public health condition, a lack of servises and multiple disease epidemics at the time. 17] As London became larger, the disposal of residential and industrial wastes became even more of a challenge, partly as a result of the mountening pressure for people to migrate to cities; the growth in urban populations stripped the availibility of basic servises such as water, transportation and electricity.  As a result, life in London in the 18th Century in the urban shantytownes was plagued by poverty, pollution, congestion, homelessness and unemployment.
The rapid expansion also led to problems of overcrowding and insanitary conditions, bringing desease, high death rates and it was therefore only through substantial migration from the countryside that London could continue to grow.  Whilst England had its small though rapidly expanding population, it became the most urbanisted country in Europe in the sense that the larger proportion of its citizens lived in a directly urban environment than anywhere else. Although there were many positire reactions to London being urbanised, many critics gave cynical views on the dramatic changes of the city.
As David Landers has said, Industrialisation in England had the effect of concentrating larger numbers of weavers and spinners in manufactoring districts which, thought still rural and not yet urban, became densely packed: full of people as Defoe wrote of the country around the Halifax in the West Riding.  As Jacques Bertin said, I admit I am still completely in the dark about what industrilisation means. Does it mean railways? Cotton? Coal? Metals? So, even at the time of the industrial revolution, urbanisation wasnt highly liked and many were bemused by the act that London was evolving.  Since urbnisation meant everything society, economy, political structures and public opinion, the most ambitious kind of history could not embrace it because the industrial revolution along with the urbanisation of London it threw Britain into upheaval and it was not a netely-definable phenomenon. There were also pessimists who, seeing its expansion, believed that urbanisation was sucking in the life-blood of the nation, among them was Dr.
Richard Price, who wrote gloomingly in 1783 that the inhabitants of the cottages thrown down in the country fly to London, there to be corrupted and perished.  This already is a strong indication that urbanisation was not the majour element in the onset of revolutionising London; this conclusion is reinforced by the analysis of urbanisation trends and it was not the traditional network of cities which was the basis of the new industrialisation process and this process was essentially located in very small towns or villages, which obviously later became big cities. 24] Urbanisation strengthened the political power of workers and of those engaged in business, with a middle class, the bourgeoisie, formed out of managers, suppliers of services, investors, bankers, industrialists, engineers and others whose well-being depended on industrialisation and urbanisation. 
Although urbanisation did bring prosperity to London, H. Shmal has suggesed that high levels of urbanisation actually limited the possiblities of productive investement, especially in the new sectors and consumption demanded from the cities and even the construction needed to be absorbed to a large share of resources, that ultimately resulted in poor living and unhealthy living conditions.  High levels of urbanisation in London created urban under-employment, and therefore, lowered productivity on the whole economy and this under-employment also lead to a too large tertiary sector, and to rigidity in the offer and mobility of the labour force.