On September 12, 1943, just four days after the announcement of the Italian armistice, a formation of German gliders appeared above the Campo Imperatore plateau on the Gran Sasso. On board were mainly Fallschirmjäger of the Luftwaffe, German paratroopers, alongside a small unit of the SS led by Otto Skorzeny. The objective was to free Benito Mussolini, who was detained at the Campo Imperatore hotel.

The action, called Unternehmen Eiche – Operation Oak, concluded in very little time. Mussolini was reached without any real combat developing on the plateau, and shortly after he left the Gran Sasso aboard a Fieseler Fi 156 Storch.

Behind the image made famous by German propaganda, that of Skorzeny next to the Duce just liberated, however, lies a much more complex operation. Oak was above all a combined airborne action, in which intelligence, reconnaissance, assault gliders, paratroopers, ground forces, and aviation were concentrated on a single objective.

From a military point of view, it still represents today a case study for the ability to achieve a strategic effect through relatively limited force, exploiting above all surprise, speed, and concentration on the decisive point.

Campo Imperatore: a natural prison

After his removal on July 25, 1943, Mussolini had been arrested and transferred several times to prevent the Germans from locating him. After Ponza and La Maddalena, he was finally taken to Campo Imperatore, in the Abruzzese Apennines.

The choice seemed particularly secure. The hotel was located at over 2,100 meters altitude, surrounded by mountains and lacking a normal road connection to the valley. Main access was via the cable car from Assergi.

It was precisely this configuration that made a conventional attack very difficult. A ground force would have had to climb the massif, capture the cable car station, and face the Italian forces present in the area.

The Germans therefore decided to completely bypass the problem: instead of reaching Campo Imperatore from below, they would bring the assault force directly in front of the hotel.

It was not simply "Skorzeny's raid"

Otto Skorzeny became the face of Operation Oak, but the raid was not an action of the SS alone and certainly not an operation conducted exclusively by him.

Overall responsibility for the execution was held by Major Harald-Otto Mors, a Fallschirmjäger officer. Most of the men assigned to the assault belonged to the Fallschirmjäger-Lehr-Bataillon, while Skorzeny participated with a smaller contingent of the SS.

The plan also provided for two coordinated actions. While the gliders would bring the men to the plateau, Mors would move from the ground against Assergi and the lower cable car station, isolating the objective and preventing the arrival of reinforcements.

It was therefore an operation built on two levels: to strike directly at the decisive point on Gran Sasso and, at the same time, to prevent relief from the valley.

Subsequent German propaganda especially highlighted Skorzeny, also because he appeared next to Mussolini in photographs released after the raid. The role of the Fallschirmjäger and Mors himself gradually faded into the background.

Why use gliders

A conventional parachute drop would have involved considerable risks. In a mountain environment, the men could have scattered on the surrounding slopes and wasted precious time regrouping.

At Campo Imperatore, the opposite was needed instead: a compact force that would arrive practically at the objective and be able to engage in action just seconds after landing.

The solution was the DFS 230, a small assault glider already used by the Germans in 1940 during the operation against the Belgian fort of Eben-Emael. Towed by an aircraft to the vicinity of the objective, it was then released and silently completed the approach in a glide.

It could carry the pilot and approximately nine equipped men. Its true strength, however, was not its carrying capacity, but the precision with which it could deposit a small unit exactly where it was needed.

At Gran Sasso this capability was pushed to the limit.

Landing where no runway existed

There was in fact no airport at Campo Imperatore. Reconnaissance photographs showed a relatively open area in front of the hotel, but the actual terrain was uneven, sloped, and scattered with stones.

To this difficulty was added the altitude, which affected aerodynamic performance.

Nevertheless, the risk was accepted because it offered an enormous advantage: instead of advancing the force towards the objective, the objective would appear practically in front of the men as soon as they exited the gliders.

The planning initially envisioned twelve DFS 230s, although two did not participate in the final phase. The formation that reached Campo Imperatore was therefore smaller than expected, but still sufficient to produce the desired effect.

September 12, 1943: the gliders on Gran Sasso

Shortly after 1 p.m., the tow aircraft took off from the Pratica di Mare area heading towards the Apennines.

During the approach, the formation did not perfectly maintain the planned sequence and the group with Skorzeny ended up reaching the area before some elements that should have preceded it.

However, the deviation did not compromise the decisive factor: surprise.

After release, the DFS 230s began their glide towards Campo Imperatore. Some landed violently and there were wounded, but most of the men managed to exit the gliders immediately and move towards the hotel.

There was no long gathering phase nor the need to reorganize the unit at a distance. The landing coincided practically with the beginning of the assault.

In modern terms, we could speak of an extremely early form of direct-to-target insertion: minimizing the time and space between the arrival of the force and the action on the objective.

The psychological effect on the Italian garrison

Traveling with Skorzeny's men was also General of the Carabinieri Fernando Soleti, whose presence was meant to help convince the Italian soldiers not to react.

The German objective was not to fight a battle on the plateau, but to prevent a battle from starting.

The sudden appearance of the gliders practically in front of the hotel, the rapidity of the action, and the presence of Soleti contributed to paralyzing the Italian response. All this occurred moreover in the chaos following the armistice of September 8, with Italian units often lacking clear orders and chains of command in disarray.

Mussolini was thus quickly reached and placed under German control without any significant confrontation developing at the hotel.

The operation as a whole, however, was not completely bloodless: during actions to control the cable car area there were Italian casualties.

Freeing him was not enough: he had to be taken away

Once Mussolini was reached, the problem of exfiltration remained.

Getting the prisoner down via the cable car would have required time and would have increased the risk of an Italian reaction. The planned solution was again aerial.

A Fieseler Fi 156 Storch landed on the plateau, one of the most effective liaison and observation aircraft of the war. Thanks to its exceptional short take-off and landing characteristics, it could operate from improvised surfaces where a conventional aircraft would have had no chance.

But Campo Imperatore remained an extreme situation: high altitude, irregular terrain and very little available space.

On board boarded Mussolini and the pilot, Captain Heinrich Gerlach. Skorzeny wanted to leave with them, further increasing the aircraft's weight.

The Storch accelerated over the rough terrain and finally managed to take off from the plateau by also using the slope in front of it. After an initially particularly critical phase, it regained speed and altitude.

Mussolini had left the Gran Sasso.

Upon reaching Pratica di Mare, he was transferred to another aircraft and subsequently taken to Germany. Shortly after, he would return to German-occupied Italy to assume leadership of the nascent Italian Social Republic.

Why Operation Quercia succeeded

From a tactical point of view, the success of the raid did not depend on overwhelming numerical superiority. The Germans instead created local and temporary superiority exactly at the point where it was needed.

They did not need to control the entire Gran Sasso. They only had to be stronger in front of the hotel for the time necessary to reach Mussolini.

This is the true key to the operation.

The use of gliders almost completely eliminated the terrestrial approach phase, while Mors's action at Assergi helped isolate the area. Surprise and speed prevented the Italian garrison from organizing an effective response before the objective had already been reached.

The DFS 230, conceptual ancestor of the assault helicopter

Viewed with today's eyes, the glider's role is perhaps the technically most interesting aspect of the entire operation.

In 1943, there was still no military helicopter capable of rapidly depositing an assault team on a small point of terrain. The DFS 230 performed, with completely different technology, part of that function.

After release, it could approach in relative silence, transport men already organized in small groups, and get them practically to the objective.

However, it had an enormous limitation: it was a practically single-use insertion vehicle. Once landed, it could not recover the force.

For this reason, Operation Quercia also demonstrates another principle that today appears normal in special operations: infiltration and exfiltration can be entrusted to completely different means. Gliders brought the force to Gran Sasso, while the Storch was used to extract the objective.

Airborne troops and special operations

Quercia is also interesting because it demonstrates how simplistic it is to oppose airborne troops and special forces.

The majority of the assault force consisted of Fallschirmjäger, while Skorzeny's men represented only one component of the deployment.

Success depended on the integration of different capabilities: reconnaissance, transport aviation, glider pilots, paratroopers, ground forces, and specialized personnel.

In other words, the special operation was not the result of a single commando's action, but of a military system capable of concentrating different capabilities on the same objective.

The glider pilots also played a decisive role. They had to bring motorless vehicles onto a mountain plateau and choose the point of contact with the ground in just a few seconds. After release, there was no second chance.

Without their technical skill, the assault force would never have reached the hotel.

A success with enormous margin of risk

Operation Quercia was not, however, a perfect action.

The formation did not reach Campo Imperatore in the planned order, the landings were particularly hard and the terrain proved worse than it appeared in the reconnaissance photographs. The takeoff of the Storch with Mussolini and Skorzeny on board also represented considerable risk.

It would have taken just one of the fundamental elements to fail for the outcome to change completely.

The lesson is therefore not that an audacious plan can eliminate risk, but almost the opposite: risk was accepted and concentrated in the insertion and extraction phases to obtain overwhelming superiority at the moment of assault.

The myth of Skorzeny

From a propaganda standpoint the result was enormous.

The photographs showed Mussolini just after liberation surrounded by the Germans and, above all, with Skorzeny always very close. The ideal narrative was already ready: a commando had reached an apparently inaccessible mountain and liberated the Duce with a spectacular coup de main.

Skorzeny quickly became an international celebrity, while the role of Harald-Otto Mors, of the Fallschirmjäger and the glider crews remained much less known.

Reducing Quercia to the formula "Skorzeny frees Mussolini", however, means losing precisely the militarily most interesting part of the operation.

The true lesson of Gran Sasso

At eighty-three years' distance, Operation Quercia retains considerable interest for the study of airborne troops and special operations.

The raid combined intelligence, reconnaissance, precision aerial insertion, area isolation, surprise, speed on target and a specific solution for exfiltration. Everything was built to achieve a political and strategic effect enormously superior to the dimensions of the force employed.

The Germans did not have to conquer the entire Gran Sasso. They bypassed the terrain and concentrated their men exactly at the point where they could produce maximum effect.

This is probably, more than the photograph of Skorzeny next to Mussolini, the true military legacy of Operation Quercia:

the ability to use the third dimension to appear directly on the decisive point, before the adversary has time to react.