The Sixth Army was first formed on 1 December 1916 under command of Ettore Mambretti. This Army was created primarily from the First Army. The First Army by August 1916, had grown from its original composition of two Corps to six Corps. Included in its Order of Battle were the XII Corps, the XX Corps and the XVIII Corps. The first two of these units were given the responsibility for the defense of the Altopiano di Asiago, a high plateau northwest of Vicenza. Because of the assignment to this sector, these two Corps were officially identified as Truppe Altipiani. The Truppe Altipiani were commanded by General Mambretti. They remained under the control of the First Army until the new Sixth Army was formed, commanded also by Mambretti. In November 1916 the First Army with Supreme Commander General Cardorna's consent, had planned “Action K”, a code name for a counteroffensive targeting Monte Ortigara using General Mambretti's Truppe Altipiani as well as the XVIII Corps. This action was cancelled due to heavy snows. On December 1, 1916 Mambretti was now placed in charge of a new Sixth Army taking his XX Corps as well as the XVIII Corps. Added to these troops was another Corps, the XXII Corps. The Italian Command would later reprise and augment the Action K plan for June 1917. The new Sixth Army under Mambretti was given the responsibility to conduct this operation, having added another Army corps - the XXVI Corps. The Sixth Army fought the Battle of Mount Ortigara in June 1917. After the failure of this attack, Ettore Mambretti was dismissed on 20 July 1917. What remained of the Sixth Army was repositioned in Val Sugana in August for defensive purposes. Then, on September 20, 1917, the Sixth Army was disbanded and re-formed into the Highland Troop Command. It was again under the command of the First Army. The Truppe Altipiani was commanded by General Zoppi and consisted of the XXVI Corps, the XXII Corps, the XXV Corps and the XX Corps. After the disastrous defeat at Caporetto the Italian Army was completely reorganized by Armando Diaz. The Truppe Altipiani Command was dissolved on March 1, 1918 and a new 6th Italian Army was formed under command of Luca Montuori. Various army corps were placed into the Sixth Army over time, including the XII French Army Corps and the XIV British Army Corps, and eventually, units of the Czechoslovak Legion of Italy. Initially the newly re-constituted Sixth Army consisted of the XIV Corps Brittanico replacing the XXVI Corps, the XII Corps Francese replacing the XXV Corps Italian and the XX Corps Italian. This Army was again placed in the Asiago Plateau between the First and Fourth Armies. The XIII Corps Italian was added later. It participated in the successful Battle of the Piave River in the mountain sector. Prior to the also successful Battle of Vittorio Veneto, the Sixth Army lost both the British Corps although a British Division remained, and the French Corps which became part of the new Twelfth Army. The XII Corps Italian was added to the Sixth Army in substitution. On July 1, 1919 the Sixth Army Command was dissolved.
