After World War I many Italians were unhappy that they did not get land from the allies, angry things in Italy, and how the government was being run.
Mussolini gathered thousands of people to form the Black Shirts, which were basically the secret police, and marched on Rome. The king did not want a revolution so he made Mussolini Prim Minister and asked him to make a new government.
Mussolini controlled almost basically every aspect of the economy. He turned it into a communist dictatorship that was very strict, called fascism. He brainwashed the children at a young age to take large nationalist pride. This may sound horrible, but the people liked it much better then the previous, more unstable government