What was the state of Italy after the First World War?

Background

At the conclusion of the First World War, Italy was a parliamentary constitutional monarchy.

The Italian Monarch was Victor Emmanuel III.

The Prime Ministers during, and following the conclusion of the First World War include:

Luigi Facta was a politician of the Italian Liberal Party who served as the last Prime Minister of Italy before the dictatorship of Benito Mussolini, leader of the National Fascist Party. Mussolini served as the dictator of Italy from 1925 to 1943, after serving as Prime Minister from October 1922 until the country transformed into a totalitarian state. 

Why was Mussolini able to gain power by 1922?

One of the contributing factors was the failure regarding Italy's claims at the Paris Peace Conference.

As a result of the failure, Fascist and Nationalist parties increased in popularity as the people of Italy believed that they were betrayed by the Allies in regards to the peace settlements of the First World War.

The appointment of Mussolini as Prime Minister

When Luigi Facta was appointed Prime Minister, Italy was in a state of political turmoil and was dealing with Mussolini's fascist uprising. 

Following the March on Rome, an organized mass demonstration in October 1922 led by Mussolini's National Fascist Party, Facta asked the King to declare martial law and order the army to stop Mussolini, however, the King refused to do so.

The day after, on 31 October 1922, Facta and his government resigned. 

As a result, the King transferred political powers to the National Fascist Party, with Mussolini as Prime Minister.

Definitions

Dictatorship: where one person or a small group of people have control over the affairs and governing of an entire country and all aspects of citizens lives.

Totalitarian: a government that is controlled by one political party. The leading party controls all aspects of life and all areas of the country.