Battle of the Western Alps

Battle of the Western Alps, June 1940

By General Francesco Roluti.   Kindly provided by Giovanni Lombardi.

(Published in “Rivista Aeronautica”, May 1948)
battle of the alps

Today, the Battle of the Western Alps can be seen in its true light: great difficulties from the standpoint of terrain—extremely difficult by nature and rendered still more so by many modern fortifications; adverse weather conditions; action that lasted a bare four days for one army, three for the other operational army, and two for some parts of the army; air action rendered almost nil by storms and dense fog; German armored divisions stopped before the difficult and well defended Alpine passes; and, in spite of all this, the fall of the French fortified outpost zone, as a result of the attack of Italian forces.

Obstacles to an Attack

Rough, mountainous terrain with summits more than 3,000 meters high and with only a few difficult avenues of approach, characterizes this French-Italian boundary, the eastern slope of which descends to the Piedmont plain and has a depth of barely 40 kilometers, while the opposite slope is three times that depth. The five obstacles of major interest from an operational standpoint, are as follows: 1. Isére— Piccolo S. Bernardo—Dora Baltea; 2. Arc—Moncenisio—Dora Riparia; 3. Durance—Dora Riparia; 4. Ubaye—Stura; 5. Roia Tenda—Cuneo.

From the operational standpoint, the fact should be noted that an advance from the valley of the Aosta by way of the Piccolo S. Bernardo, descending the valley of the Isère in the direction of Albertsville and Grenoble, would cause the fall of all French defenses in the Alps area. The obstacle, Dora Riparia–Moncenisio—Arc, runs parallel to this direction of advance.

The obstacle Stura—Ubaye guards the route of an advance along the coast toward Marseilles and Nice. The most profitable effort would be in the direction of Piccolo S. Bernardo, but it is longer and more difficult. It would be facilitated by an attack from the direction of the Lyons—Valence front, directed against the rear of the French defenses facing the Piccolo S. Bernardo. Such a situation was possible, but failed to develop during the battle in question.

All the various lines of penetration, including minor ones by way of secondary passes, were strongly barred by the French with modern fortifications, well armed and manned. Complex positions equipped with artillery and automatic weapons, excavated in the rock with underground approaches and communications, constituted a powerful zone of resistance. Intermediate positions for automatic weapons and antitank guns were placed in front of the main defenses. Still further advanced, a few hundred meters from the international frontier, there were small positions, isolated casemates and concrete emplacements of various types for automatic weapons or antitank guns, often camouflaged as small villas surrounded by vegetation. Altogether, the fortified system measured from 20 to 50 kilometers in depth and presented a deep fire wall opposing every direction of penetration. France already favored by naturally strong defense positions, had modernized and enlarged the permanent defenses.

Situation Preceding the Operation

After the East African and Spanish campaigns, Italy needed much time in which to prepare for a European conflict. The head of the government had estimated that Italy would not be able to enter a conflict before 1943. Badoglio, chief of the general staff at the time, believed that Italy would not be ready even by 1943, but events and individuals changed the estimates. When, in September 1939, Hitler began the Polish campaign, he wrote to the Italian chief of state that the dispute concerned Northern Europe only, and that Germany felt capable of handling the matter alone. Italy, therefore, would be able to remain quietly apart; Germany was satisfied with the good will of the Roman government. The Italian chief of state, perhaps suspicious of the existence of pacts regarding “living space” between Germany and Russia, gave orders for the reinforcement of the Italian frontier in the direction of Germany, and saw to it that the western frontier was properly guarded, declaring Italian non-belligerency. After the Polish campaign, there was a break in the military operations, suddenly ended on 9 April 1940 by the German invasion of Norway. On 10 May, the powerful German military machine turned against Western Europe, quickly crushing all resistance. Holland and Belgium laid down their arms. The English army in Belgium was forced to re-embark. The entire northern portion of the French army was overthrown. Badoglio states that at that time the chief of the Italian government regarded the fall of England as imminent, and was overcome with a mad desire not to be excluded from the victor’s feast. Perhaps [the real motivation] was the specter of Hitler and Stalin dominating Europe that appeared threatening to him, and, in the light of what we now know, this was no idle fear. The decisions of Rome were made rapidly. On 26 May, the chief of the government communicated to Badoglio that he had written to Hitler, informing him that he would be ready to declare war by 5 June. On the 10th, Italy officially declared war against France and England.

In the meantime, the Italian army remained in defensive positions in the Western Alps with its large units and artillery drawn well back. At least twenty-five days would normally have been required to make an offensive deployment. It is not known on the basis of any official documents why steps were not taken immediately after 26 May to redeploy the forces for an offensive operation. The French general staff had originally intended to invade the Paduan valley, while holding the German army before the Maginot line, but by 26 May such a plan was impossible in view of the heavy losses that had been suffered in Belgium, and the turning of the Maginot line on the north.

Events in France continued at a rapid pace. On 9 June, the von Block group of armies reached the Seine a few kilometers from Paris, and on the same day the von Rundstedt group of armies attacked toward the Marne. The French Army, under the impact of tanks and German Stukas, was literally pounded to pieces. On 17 June, Marshal Petain, new head of the French government, sought an armistice.

The Italian army, on the western frontier, remained on the defensive until 16 June, when orders were given to prepare for offensive operations. On the afternoon of the 20th, the order was given to all forces along the entire front, from the Piccolo San Bernardo zone to the sea, to attack at 0300 hours the following morning with the aim of penetrating into the French territory as far as possible. The armistice, which had already been asked for by the French, and the occupation of nearly two-thirds of France by the Germans, did not allow time for a deep penetration in the Alps in the direction which would undermine the entire system of defenses. The effort was made, however, to penetrate everywhere as far as possible, with a view to improving, from a defensive point of view, the Italian political boundary.

Attention has already been called to the amount of time that would likely be necessary for changing from a defensive to an offensive status, at least twenty-five days. Actually, only four days were allowed for this. The natural difficulties of a high mountain zone, rough, broken, and lacking in communication routes, were increased by stormy weather and heavy snowfall. These difficulties forced the Italian forces to attack only on the right (the Piccolo San Bernardo zone) initially. The forces which were facing one another over the entire front were as follows:

The French had 200,000 men, well established in modern fortifications, unaware, for the most part, of the disastrous events which had befallen the French forces in the north and in the center.

The Italian forces included 300,000 men in the western army group of two armies:

The First Army, from the sea to Monte Granero (not included); the Fourth Army, from Monte Granero to Monte Rosa (not included). There were 100 Italian bomber planes and 200 fighters, but they were operating under directives of the army chief of staff. Each army had reconnaissance aircraft at its disposal, the reconnaissance to extend as far as the Marseilles front, the Durance river, Grenoble, the middle Isère, and Lake Bourget. The army chief of staff was to provide longer range reconnaissance, and information required by the army could be requested from him.

The Operation

On 21 June, only the mountain corps of the Fourth Army attacked in the Piccolo San Bernardo zone. Its objective was to open a way into the Isère Valley. Destruction of the fortified works of Bourg St. Maurice was assigned to the bombing aviation, from dawn to 0630, but no longer. The artillery preparation began at 0830. At 0900, the advance of the mountain forces was to begin.

In the meantime, German armored forces had reached Lyons, and were preparing to attack in the direction of Chambery and Grenoble, in the rear of the defenses of the valleys of the Isère, Arly, and Arc. This operation was scheduled for the 21st or the 22nd. In the early hours of the morning, Italian bombers, in spite of the fog, carried out the prescribed bombing action. The reconnaissance planes scoured the upper valley of the Isère and the Valley des Glaciers. At 1000, a half hour late, owing to difficult movement because of the deep snow, the mountain forces attacked from the heights of la Seigne, Piccolo San Bernardo, du Mont, and the traversable mountains between them. In spite of lively French resistance, they overthrew the defenses, advancing over the entire attack front. The French, however, detonated a mine field, cutting the Piccolo San Bernardo—St. Maurice road. Engineer units of the Trieste Motorized Division quickly intervened and repaired the road. By evening of 21 June, the mountain forces, in spite of the deep snow and adverse weather conditions, had succeeded in advancing between two and four kilometers and in outflanking the Traversette fort, which was laying its fire down in the direction of the Piccolo San Bernardo.

The other large units of the Fourth Army had thrust formations into the valley of the Arc (Moncenisio sector), and in the Monginevro sector had penetrated one kilometer in the face of heavy fire from Briançon fortifications. The intervention of the air forces was requested in this zone, whereupon these forces heavily bombed Forts Janus, Goudran, and Chenaillet. Adverse weather conditions, however, interfered with efficient air action.

On 22 June, the First Army also began an attack from Monte Granero to the sea, with the intention either of forcing its way into the valley of the Ubaye and continuing afterwards through the valley of the Durance in the direction of Marseilles, or into the Nice area and then continuing in the direction of Marseilles.

Maximum cooperation was requested of the 1st Air Squadron, but the activity of the bombers was greatly limited by continued bad weather. It was possible to bomb effectively only the fortifications west of Briançon, facing Monginevro, and the fortifications of Monte Agel, north of Monaco, facing Ventimiglia and Mentone. The army chief of staff, consequently, warned the surface units that they could not substitute aviation for artillery in the high mountains.

On 22 June, the Fourth Army continued the attack started the day before. The forces were forced to open a passage through the snow, which in some zones was three meters deep. In the Piccolo San Bernardo sector, it was necessary to repair the road leading to Bourg St. Maurice in order to continue on through the valley of the Isère toward the German armored forces already mentioned. It was, likewise, necessary to silence the Traversette fort with artillery fire. The fort was already outflanked, but was laying its fire down on the approach route to Bourg St. Maurice. A little after 1200 on 22 June, an auxiliary passage was completed alongside the first cut, which permitted the passage of motorized forces. About the same time, Fort Traversette appeared to be reduced to silence, as it no longer replied to the fire of Italian artillery. A second break was discovered in the road beyond the first break which had been repaired. The night of 22-23 June, it was announced that the German Sixteenth Armored Army would begin the offensive thrust against Grenoble and Chambery, in the rear of the French forces by daybreak on the 24th. The commander of the Fourth Army, facing that area, hastened the Italian advance toward the Isère Valley. He ordered an armored battalion of the Littorio Armored Division to push in the direction of Bourg St. Maurice, coordinating this movement with the advance of the mountain units over the slopes leading to the Isère and adjacent valleys. The leading armored company, after the first break in the road had been passed and two successive wire entanglements overcome, ran onto a mine field. One tank was knocked out and four others damaged sufficiently to halt their progress. The battalion commander believed that this was the result of well-aimed antitank artillery fire, and ordered the subordinate unit to fall back until Italian artillery could intervene. This error permitted the most favorable moment for the execution of their maneuver to pass. Italian units, advancing over the heights, were, on the evening of 24 June, in contact with the permanent defensives of Séloge, had advanced to beyond Seez, and from the Col du Mont had reached the Isère.

In the Moncenisio sector, from 22 to 24 June, Italian forces took the advanced French fortifications and centers of resistance. Lanslebourg, Termignon, and the route on the Arc valley floor, had been reached as well as the eastern edge of the Briançon basin in the Monginevro sector.

On the 22d, the First Army continued the attack with two groups of forces concentrated on its wings. The right group proceeded in the direction of the Ubaye valley, and the left, in the direction of Monaco and Nice. In the center, a smaller group acted as the connecting link. On the morning of 23 June, all available bombing aviation attacked the French works on Monte Agel, in support of the left group of forces. At about 1100, the air bombing had to be stopped, however, on account of bad weather.

On the evening of 24 June, the situation of the First Army was as follows: Mentone completely occupied; in the Ubaye valley, and over the remainder of the front, French advanced positions were either taken or surrounded.

Generally speaking, by the evening of 24 June, Italian forces had seized possession of the French advanced zone everywhere over the entire Alpine front of 200 kilometers, to a depth of from eight to 32 kilometers, and were in contact with the French main defense zone. The German armored units already referred to had not succeeded in reaching their objectives, as French units effectively barred the main roads up the valleys by which the German units attempted to ascend.

At the request of France, an armistice was agreed to on 24 June, and was signed at 1915 the same day. Cessation of hostilities was effected in France proper, and in her overseas possessions, at 01:35 the following day.


It must be borne in mind that the offensive action was of brief duration, only four days for the Fourth Army, three days for the First Army, and twelve days for the left wing of the Second Army Corps, which was a part of the First Army.

The difficulties of the mountainous zone were accentuated, both by the unfavorable weather conditions and by the effective fire from the French fortifications. While the French had fallen in Belgium and northern France as a result of Stuka and tank attacks, in the Alpine zone there was no collapse because of lack of action on the part of the armored and air arms. The same German armored units which had crushed everything before them were halted before the Alpine passes between Lyons and the Isère. They did not have the assistance of the Stukas, nor motor-transported troops to an extent sufficient to conquer the Alpine passes by ground attacks.

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