The Industrial Revolution has been a process of passing of the medieval's economic regulations. This process is one of the most important facts in English's history as it led to the growth of two systems of thought: Economic Science and Socialism. Economic's history has been influenced by four important economists: Adam Smith, Malthus,Ricardo and John Stuart Mill. All these important figures wrote Essays about basis of Economy who led to importants step further in this world. There are two fundamental facts who led to Industrial Revolution: Growth of population and agrarian revolution. In particular, the decrease of rural population was caused by the destruction of the common fields system, remplaced by the Enclosures, and the consolidation of small farms into larger ones. Another important fact was the agricultural sdvance, caused by a more scientific approach. People started to extend arable coltivation, improve the breed of cattle,organise in agricultural societies and to introduce the rotations of crops. All these activities led to a growth of industry, also helped by mechanical inventions such as the water frame, Crompton's mule,Spinnig-Jenny and the self-acting Mule. The most important invention was the steam engine. A further step was made with the iron industry, by the smelting using pit-cool. Then, there was also an improvement of means of communication with a canal system, more articulate streets and a railroad. The Industrial Revolution implied also negative aspects such as periods of over-production and depression. Mainly, the revolution brought to the substitution of factory system for the domestic system (autarchy). All these aspects led to social changes in country life,especially of political power and classes, because farmers shared landlords' prosperity. As a consequence, there was a creation of a new distinct class and changes in normal habits. Finally, another negative aspect was misery, caused by rise of prices and the conditions of working under the factory system.