The Milizia Volontaria per la Sicurezza Nazionale (MVSN, "Voluntary Militia for National Security"), commonly called the Blackshirts (, CCNN, singular: Camicia Nera) or squadristi (singular: squadrista), was originally the paramilitary wing of the National Fascist Party and, after 1923, an all-volunteer militia of the Kingdom of Italy. Its members were distinguished by their black uniforms (modelled on those of the Arditi, Italy's elite troops of World War I) and their loyalty to Benito Mussolini, the Duce (leader) of Fascism, to whom they swore an oath. The founders of the paramilitary groups were nationalist intellectuals, former army officers and young landowners opposing peasants' and country labourers' unions. Their methods became harsher as Mussolini's power grew, and they used violence and intimidation against Mussolini's opponents. In 1943 the MVSN was integrated into the Italian armed forces.