Prior to the Industrial Revolution, there were few settlements which could be considered as urban. Population was concentrated mainly on lands which were agriculturally productive.
The functions of the early cities were mainly political. Administrative and garrison towns were, therefore, often set up to control conquered territories.
As pointed out earlier, the inhabitants of such urban areas were dependent on rural areas for their food supplies and other necessities of life, which were thoroughly exploited for the purpose.
Gradually, the population of such pre-industrial cities came to be dependent on trade, which occurred within the cities; and by the time the Middle Ages arrived, such cities became centres of economic rather than political activities.
With the Industrial Revolution, which first began in England and then spread to other parts of Europe, the process of modern urbanisation truly began.
Several economic opportunities became available in industrial centres, leading to massive rural-urban migration, which resulted in a dramatic redistribution of population.
The main factor contributing to the urbanisation process during and after the Industrial Revolution was economic in nature. As employment and economic opportunities offered inducements to people to migrate from the rural to the urban areas, changes occurred, not only in their residence, but also in their occupations.
In addition to the attraction provided by employment opportunities, other factors affecting socio-cultural conditions were also instrumental in influencing rural-urban migration.
Educational opportunities, health services, housing conditions, public services facilities, cultural and recreational opportunities, social legislation bearing on working conditions, social welfare and relief program all these were invariably superior in urban rather than in rural areas, making the former more attractive for residence than the latter.
The weakening of the bond between individuals and the soil was also responsible for encouraging people to migrate to urban areas in search of fresh opportunities for self-advancement.
Even in the twentieth century, rural-urban migration has continued to play an important role in the process of urbanization in the currently more developed countries of the West.
The economy factor continues to be important for there is more demand for labour in the secondary and tertiary sectors in the cities than in the agricultural sector in rural areas.
The factors determining the socio- cultural conditions mentioned earlier have become even more important for influencing rural-urban migration, betterment in educational opportunities, social legislation, and the general conditions of living.
In such countries as the USSR and Japan where industrialisation set in later than in Europe, planned economic and social growth has been responsible for certain developments which have relevance in the context of the distribution of population in rural and urban areas.
The planned industrial economy of Japan has led to a great deal of rural-urban migration motivated by economic factors, and has resulted in a highly urbanised modern society.
In the USSR, despite the efforts of the Government to encourage people to settle in sparsely populated territories, migration from rural areas to the cities has been heavy because of the ample employment opportunities available in the latter.
In the USSR, efforts are made by the Government to arrest the growth of the largest cities rather than to discourage them from migrating from rural to urban areas.
While in the more developed countries, the “pull” factor has been important for accelerating the process of urbanisation as a result of rural-urban migration, in the less developed countries, the “push” factor appears to be more important.
It has been observed that because of the difficult conditions of living in rural areas of these countries, people migrate to urban areas in the hope of finding a better life.
Conditions of widespread poverty, indebtedness, underemployment and fewer opportunities for cash-earning employment motivate people to leave rural areas as they believe that economic conditions in urban centres are likely to provide a comfortable life.
Such a massive migration from rural to urban areas has sometimes led to “over-urbanisation,” that is, these countries have had a larger urban population than appears to be justified by their levels of industrialisation.