During World War II the regiment was assigned to the 21st Infantry Division "Granatieri di Sardegna", with which it served in occupied Slovenia.

In March 1796, Napoleon Bonaparte arrived in Italy and took command of the French forces, with which he defeated the Royal Sardinian Army in the Montenotte campaign within a month.

After the defeat in the Montenotte campaign King Victor Amadeus III was forced to sign the Treaty of Paris, which ceded the Duchy of Savoy and the County of Nice to France and gave the French Revolutionary Army free passage through the Kingdom of Sardinia towards the rest of Italy.

On 24 March, the new King met with the Austrian Field Marshal Joseph Radetzky at Vignale and agreed to an armistice, which ended the First Italian War of Independence.

[4][6][7][11] On 9 March 1859, in preparation for the Second Italian War of Independence, both regiments of the Grenadiers of Sardinia Brigade formed an additional depot in Alessandria.

On 23 May 1915, Italy entered the war and the Brigade "Granatieri di Sardegna" was deployed, as per tradition, on the extreme right of the Italian front at Monfalcone on the shores of the Adriatic Sea.

On 5 June 1915, the brigade crossed the lower Isonzo river at Pieris and advanced to the foot of the Karst plateau, which blocked the way to the city of Trieste.

On 10 November 1915, the Italians began the Fourth Battle of the Isonzo and the Brigade "Granatieri di Sardegna" attacked Height 188 in the Oslavia sector.

On 10 August, the Austro-Hungarian forces abandoned their attempts to retake Monte San Michele and fell back to their second line of defense along the summits of Nad Logem, Veliki Hribach, and Pečinka.

Between 11 and 14 August 1916, the grenadiers tried to break into the new Austro-Hungarian line, but the heavy losses the brigade had suffered in the preceding days and exhaustion prevented any success.

[4][12] On 14 September 1916, the Seventh Battle of the Isonzo began and the brigade attacked the Austro-Hungarian line between the hill of Miren Castle and Veliki Hribach.

On 28 December 1916, both regiments of the Brigade "Granatieri di Sardegna" were awarded a Silver Medal of Military Valor for their conduct during the first two years of the war.

On 22 May the brigade moved to the Karst plateau, where the next day, on 23 May, the 1st Grenadiers Regiment's I Battalion entered the frontline to the West of the village of Sela na Krasu.

On 24 May, both regiments of the "Granatieri di Sardegna", as well as the brigades "Mantova" and "Padova", attacked the same heights once more in an attempt to reach Sela na Krasu.

The next day, on 25 May, the grenadiers again tried to open a way to Sela na Krasu, but quickly the futility of further attacks became obvious and the exhausted Italian forces were ordered to fortify the conquered positions.

However already the next day, on 6 June 1917, the grenadiers were sent back into the first line to stop the Austro-Hungarian counterattack at Flondar, which had already succeeded in driving the Italians off of some of the recently conquered heights.

During the retreat the brigade continuously clashed with Austro-Hungarian and German units and on 30 October the commander of the 2nd Grenadiers Regiment, Colonel Emidio Spinucci, fell in combat against enemy forces.

[1][4][12][13] On 17 November 1918, the Brigade "Granatieri di Sardegna" arrived in Rijeka and, together with French, British, and American troops, occupied the city.

At 18h in the evening of 11 September 1919, D'Annunzio arrived in Ronchi and sent four officers to Palmanova, where they forced the commander of the army's auto park to hand over five Lancia 1ZM armored cars and 35 trucks.

On 9 September, the Germans attacked in full force and the grenadiers, which suffered heavy losses in the fighting, had to abandon the three southernmost strong points.

On 10 September 1943, the grenadiers, the Lancieri di Montebello, reinforcements sent by the "Sassari" division, and hundreds of armed civilians fell back to a defensive line before Porta San Paolo for a last stand.

The future Italian president Sandro Pertini brought a detachment of Socialist resistance fighters to Porta San Paolo and around 12:30 the Catholic Communist movement arrived with further reinforcements, including famed actor Carlo Ninchi.

Before surrendering the Italian soldiers handed thousands of their weapons over to the civilian population, which was quick to form an organized resistance movement in the city.

On 11 November 1942, the Special Grenadiers Grouping and the Marine Regiment "San Marco" landed in Corsica and proceed to occupy the island.

On 13 September 1943, when troops of the German Sturmbrigade Reichführer-SS, which had its headquarter in the nearby village of Quenza, arrived at the positions of the grouping's II Battalion in Zonza, fierce fighting erupted, which lasted all day.

The next day, the grouping's I Battalion, which was based in the village of L'Ospedale, allied with Corsican resistance fighters and blocked German units from using the road arriving from Porto-Vecchio.

The same day, a detached company of II Battalion, which was based in the village of Levie, was attacked by armored units of the German 90th Panzergrenadier Division, which had retreated from Sardinia to Corsica.

On 23 September 1943, the III Battalion's troops clashed with German forces in Palavese, which by evening retreated and thus opened the road to liberate Porto-Vecchio.

[4][7] From 10 to 13 October 1943, the Special Grenadiers Grouping, which had joined the Italian Co-belligerent Army, was shipped from Corsica to Sardinia, where it was sent to the city of Iglesias.

On 21 November 2017, the detachment in Spoleto was used to reform the 2nd Grenadiers Battalion "Cengio", which remained assigned to the 1st Regiment "Granatieri di Sardegna".