The middle class evolved due to the Plague which killed off many people. When Europe’s population decreased, they needed more workers in order to survive. So, the middle class evolved. Then during the Industrial Revolution when many inventions were being created which made manufacturing to be done more quickly and efficiently, the middle class gained power.
People were able to make more money by using these machines to product products. Living conditions improved for the middle class. Fewer people were poor compared to the population prior to the revolution. Factories were built and employed people in the middle class. They could make more money doing these jobs than working on a farm. Many middle class people moved from the country to the city to work in these factories.