On 22 June 1921, Argo Secondari convened a general assembly of members and sympathizers, which saw heated debates between supporters of fascism and anti-fascists.

At a subsequent meeting on 27 June 1921, the new Directory was elected, a triad of which Secondari was president together with Lieutenant Ferrari and Sergeant Major Pierdominici.

During the assembly, it was decided to create a Battalion of the Arditi del Popolo, whose task was to defend the seats hit by squadristi violence.

The Battalion was immediately supported by the Proletarian defense Formations, which came to be set up in response to the Fasci Italiani di Combattimento and was initially named Association of the Arditi del Popolo.

On the occasion of the anti-fascist rally, organized by the Proletarian Defense Committee, at the Botanical Garden of Rome, Secondari, at the head of the Arditi, paraded through the crowd in ovation, in a march attended by about two thousand people.