[2] The revolutionary wave of 1848-49 left a mark on the young Mirri, who began to associate with democratic thinkers of his home region.

His father, wanting him to follow a veterinary career, and trying to keep him away from radical circles, sent him to Rome in 1853 to join his brother Pietro who was studying architecture.

[3] Upon the departure of the Austrians from Bologna, on 12 June 1859, Emilia-Romagna rebelled against the restoration of the Papal States and a corps of volunteers was formed in Imola.

[2] In the following months he served in the Naples police and in January 1861 he was sent to Isernia to quell a peasant revolt led by Bourbon officers.

In 1866 he took part in the battle of Custoza in the 53rd grenadier regiment and then in the campaigns to repress brigandage (1868-69) and to deal with cholera in Sicily (1869).

[7] Having become a trusted associate of Francesco Crispi, in September 1894 Mirri was appointed extraordinary commissioner for Sicily,[4]: 322  where in that period he commanded the XII Army Corps.

Here he focused on combatting organized crime, which in his view was the main cause of deprivation among farmers and sulphur mine workers, whose working conditions he sought to improve.

In the course of this he criticized the Palermo judiciary, and one of the prosecutors he called into question made public a letter from August 1895 in which Mirri had asked for a mafia member, Saladino, to be granted bail.