During the 19th century Italy started to unify into one country, and in 1861 Manfredo Fanti signed a decree creating the Army of the Two Sicilies.

This newly created army's first task was to defend its territorial gains against Legitimists in southern Italy, who remained loyal to Francis II of the Two Sicilies.

The first two tasks of the new organization were the repression of brigandage in southern Italy against irregular and hit and run forces (mixed with bands of various criminals), who refused to accept the suppression of the Kingdom of Two Sicilies, and the Third War of Italian Independence.

On 8 February 1885, a corps of fewer than 1,000 soldiers landed at Massaua, Eritrea, starting the creation of an Italian colonial empire.

The following year, as part of the Italian collaboration with the international pacification program after the revolt against the Turkish domination in Cyprus, another corps disembarked at Candia.

This regulation structure was very similar to the 1859 version which was inspired by the Royal Sardinian Army penal code of 1840 which preceded the Albertine Statute of 1848.

It supported Benito Mussolini's Fascist regime because of its expansionist ideology and reversal of previous governments' defense cuts.

The Regio Esercito (Royal Army) was one of the largest ground forces in World War II, during which it was one of the pioneers of the use of paratroopers.