​The important reforms, implemented by the General Staff of Vittorio Emanuele II with the aim of transforming the old Sardinian Army into the first Italian Army, started soon after the end of the Second War of Independence at the end of 1859. The small regional Army of the King of Sardinia was not sufficient to carry out the tasks that the new national Army would have carried out.

In the last months of 1859 there were meetings with all military forces of the Country, concluding a first organizational phase in March 1861; it was then that, by note no. 76 of 4^th May 1861, the Minister Fanti “announced to all Authorities, Corps and military Offices that the Royal Army would be called Italian Army, and the previous denomination of Sardinian Army remained abolished”.

Before the integration of the other two pre-unitary Armies (the Borbonico and the Garibaldino), the Army had a structure based on five Army Corps, four of which were composed by three divisions with two Infantry brigades, two Bersaglieri battalions and three Artillery battalions each, as well as a Cavalry brigade on 3 regiments. Outside the Army Corps there was another Cavalry division with four regiments and two horse artilleries. The Infantry and the Cavalry regiments were organized in four battalions/squadrons.

The Artillery consisted of eight regiments: the 1​^st was a regiment of workmen; the 2^nd , the 3^rd and the 4^th were part of the artillery square, each on 12^th companies; the 5^th, the 6^th, the 7^th and the 8^th were “field artillery”, each with 12^th​ batteries. The horse batteries were part of the 5^th​​ regiment.

The Engineer Corp was organized in two regiments of 16 companies.​