The "Sassari" Brigade was constituted on 1st March 1915 in Tempio Pausania, with the 151st and 152nd Infantry Regiments.
During the Great War the Brigade fought with too much courage to be considered "a special assault unit" and it was feared by the Austrians.
For its heroism during the First World War, the Flags of the two Regiment were awarded with two Gold Medals to Military Valour. For the effect of law 11th March 1926 about the reorganization of the Army, it included the 151st and 152nd Regiments and the 12th "Casale" Infantry Regiment, getting the name of 12th Infantry Brigade.
Later the Brigade and the 34th Artillery Regiment became part of the 12th Land Military Division of Trieste; in 1934, when the Great Unit was named 12th Infantry Division of Timavo, the Brigade became 12th Infantry Brigade of Timavo.
In 1939, with the abolition of the brigade level, the 12th "Sassari" Infantry Division was formed including the 151st and 152nd Infantry Regiments and the 34th Artillery for Infantry Division.
In 1941 it also included the 73rd CC.NN. Assault Legion; that Legion, employed on the western alpine front in 1940, from 1941 to 1943 it carried out anti-guerrillas in Yugoslavia before being repatriate and deployed in Rome.
Following the armistice, the Division was dissolved on 10th September 1943, after having participated in the defence of Rome from the attacks of German Forces.
On 1st December 1988 the "Sassari" Motorized Brigade was constituted in Sassari, including the 151st "Sette Comuni" Motorized Battalion, the 152nd "Sassari" Infantry Battalion and the 45th "Arborea" Infantry Battalion.
Since 1st January 1991 it became "Sassari" Mechanized Brigade and included the Command and Tactical Support Unit, the 151st and 152nd "Sassari" Infantry Regiments and the 45th "Reggio" Regiment.
On 26th September 2003 the 45th "Reggio" Infantry Regiment was changed into 5th Engineer Regiment that was included in the "Sassari" Mechanized Brigade.
On 1st December 2009, the General staff of the Army ordered the relocation of the 3rd Bersaglieri Regiment from the "Mameli" barracks in Milan to the "Salvatore Pisano" barracks in Capo Teulada, leaving the 132nd "Ariete" Armoured Brigade and passing to the dependencies of the "Sassari" Mechanized Brigade.