Completed in 1935, the Belgian Fort Eben Emael represented the forefront of modern military defense technology. It was one component in a defensive network protecting the city of Liège. In May 1940, its strategic position placed it directly in the path of Germany’s westward advance, overlooking the Albert Canal bridges at Vroenhoven, Canne, and Veldwezelt.
Each bridge had a garrison and was prepared for demolition. Concrete bunkers with dedicated demolition crews overlooked the bridges, ready to destroy them on command or if overrun by enemy forces. Should the bridges be destroyed, the guns of Eben Emael would prevent any German attempts to construct replacements. If the demolition failed or the crews were captured, the fortress guns were capable of destroying the bridges directly.
Germany’s Assault Plan
In the fall of 1939, General Kurt Student, a seasoned World War I pilot and commander of Germany’s airborne division, was summoned by Hitler. Aware of Eben Emael’s reputation, Hitler proposed taking the fort with specialized glider-borne troops. Student, an experienced glider pilot himself, requested time to evaluate the feasibility of this plan and returned the next day to confirm it was possible.
Hitler then discussed the capture of the French Fort Douaumont in World War I, highlighting the effectiveness of heavy artillery. He revealed a new German weapon: the hollow-charge explosive (‘hohlladung’). This device could focus its blast, creating a jet of molten metal capable of penetrating thick concrete and steel fortifications. It was available in 20-pound and 110-pound sizes, with the larger version comprised of two parts for easier transport. This weapon would be a key component in the assault on Eben Emael.
Germany’s Military Innovation and Glider Development
Following World War I, the Treaty of Versailles limited Germany’s ability to openly develop an air force. As a result, Germany focused on training pilots through unpowered gliders, which were not restricted. Many of these early pilots were trained within the National Socialistische Flieger Korps, part of the Hitler Youth organization. This focus on glider training led to Germany having a large number of skilled sailplane pilots before World War II.
Germany also experimented with larger glider designs, including ones intended as flying laboratories. After witnessing a demonstration of one of these gliders, Luftwaffe General Ernst Udet envisioned a military version. This concept led to the development of the DFS 230, a troop-carrying glider designed to be towed by the Junkers 52 transport aircraft. Famed test pilot Hanna Reitsch was involved in testing and refining the DFS 230 design.
The DFS 230 could carry significant cargo and was designed for concentrated troop deployment, in contrast to scattered airborne units. Adolf Hitler viewed this glider as a valuable tool for specialized military operations. General Kurt Student was tasked with selecting and training a specialized strike force to utilize the DFS 230.
The Specialized Sturmabteilung Force
Student selected Captain Walter Koch, a paratrooper, to lead the assault force. Koch organized his volunteers into four combat teams, each with a specific strategic target: the Eben Emael fortress and three key bridges along the Albert Canal (Veldwezelt, Canne, and Vroenhoven).
Lieutenant Schact’s “Beton” group targeted the Vroenhoven bridge, while Oberleutnant Altman’s “Stahl” was assigned to Veldwezelt. Leutnant Martin Schaechter’s “Eisen” aimed to capture the bridge at Canne. Oberleutnant Rudolf Witzig and his small “Granit” team, comprised primarily of engineers, were tasked with the formidable challenge of taking the Eben Emael fortress.
Preparations for the Eben Emael Raid
Near Hildesheim, Germany, the German assault force trained rigorously on fields laid out to replicate Eben Emael’s dimensions. They also practiced on fortifications from the former Czech Benes Line, perfecting glider exits, weapon deployment, and the use of 110-pound shaped charges.
The Germans meticulously studied Eben Emael, using models, aerial photos, and postcards. They received insights from Belgian deserters, German construction workers familiar with the fort, and engineering experts who explained fortress design. Detachments tasked with bridge assaults conducted repeated practice on similar structures within Germany.
Glider pilots honed their skills, aiming for pinpoint landings within 20 meters of their designated targets. They practiced on old Polish fortifications at Gleiwitz, knowing their landings had to be quick to minimize exposure to enemy fire. As the mission would begin at dawn, pilots needed to be flawlessly precise in the dim light.
Security and Specialized Weapons
The operation demanded the strictest secrecy. Communication was restricted, and the unit operated under deceptive names. Witzig’s soldiers, in addition to standard infantry gear, carried specialized explosives: small charges for viewports and gun barrels, flamethrowers, Bangalore torpedoes, and charges to disable observation cupolas which directed the fort’s artillery.
The Germans deployed a formidable new weapon: the ‘hohlladung’. This shaped charge used the “Monroe Effect” to generate a devastating blast that could pierce steel or concrete. Witzig’s paratroopers were trained to carry and assemble these heavy devices on the battlefield.
Preparations for the Assault
Witzig, the commander, withheld the use of the hohlladung weapon during training exercises against steel and concrete. He avoided using readily available Czech fortifications, opting to keep his men unaware of the weapon’s destructive potential. This secrecy was considered vital to prevent information leaks that could jeopardize the mission.
In February of 1940, Granit’s glider forces conducted a full-scale rehearsal of the attack they would launch against the Benes Line. They practiced with their full arsenal, with the crucial exception of the hollow charge weapon. Witzig only allowed its detonation against soil, creating craters that revealed little about its power. This exercise ensured the strike force was completely prepared, aside from knowing the specific target and its official name.
The gliders that would transport the Sturmabteilung Koch were shipped from Hildesheim using sealed furniture vans. They were transported to Ostheim and Butzweilerhof airfields near Cologne. Upon arrival, the DFS 230s were assembled under the cover of night and smoke designed to obscure the process. Security measures included guarded fences and matting to prevent observation. Once assembled, the gliders were moved into newly constructed hangars for concealment. The Luftwaffe mechanics involved in the assembly were then kept in isolation, mirroring the restrictions placed on the strike force. Throughout all of this, the strike force’s training continued rigorously.
Witzig’s Mission Begins
On May 1, 1940, Witzig’s unit received an alert, escalating the tension that had been building for days. On the night of May 9th, they learned the operation was finally underway. As dusk fell, airfield lights were turned off. Field kitchens began serving the troops, and Junkers 52 tow planes arrived. Ground crews joined gliders to their tow planes on the darkened airstrip, completing the meticulous process of loading weapons and carefully inspecting tow ropes. The soldiers, their preparations complete, now had nothing to do but wait and pass the anxious hours.
Shortly before midnight, Witzig informed his men that their objective was a fort within Belgium’s defensive network. Around 3:00 AM, the order to board the gliders came. One by one, the Junkers lifted into the night sky, each dragging a glider behind. The formation flew through the darkness, aiming for an altitude of 8,500 feet. Guidance for the lead aircraft came from a chain of Luftwaffe beacons. Apart from a near collision that caused a terrifying incident, the flight remained uneventful.
Witzig’s glider, piloted by Corporal Pilz, was forced into a violent dive to mirror the evasive maneuvers of its tow plane, which was avoiding another aircraft. The sudden movement snapped the tow line. Pilz, unable to reach Eben Emael, landed the glider in a weedy field. Witzig, enraged, organized his men to clear a makeshift runway. He then located an officer of a nearby German unit and obtained a car, returning to Ostheim airfield to secure a replacement Junkers.
Precious time was slipping away. Further ahead, another glider in the Granit force received the premature release signal from its tow plane. Corporal Bredenbeck, the glider pilot, obeyed the command despite knowing they hadn’t reached the target. He was forced to land approximately 25 miles from the fortress. With this loss, Granit’s assault force had dwindled to 70 men.
“Airplanes Are Overhead! Their Engines Have Stopped!”
At just past 4:00 AM, the aircraft sighted their final guiding beacon, a light situated on a hilltop northwest of Aachen. The original plan specified releasing the gliders here, but no signal was given. The tow planes and gliders were flying too low and ahead of schedule, so the formation continued for an additional 10 minutes until the designated release altitude of 8,500 feet was reached. The gliders then detached from the tow aircraft and continued alone in the darkness. Dutch antiaircraft units around Maastricht opened fire into the night sky.
Belgian forces along the Meuse and Albert Canal were alerted. Reports started filtering in from the Canne bridge and a nearby outpost, indicating unidentified aircraft were approaching. In command at Eben Emael, Major Jean Jottrand had previously ordered the above-ground barracks emptied and destroyed to provide clear firing lines. He analyzed the incoming reports, particularly one that stated cryptically: “Airplanes are overhead! Their engines have stopped! They stand almost motionless in the air!” No one had the experience or context to interpret this unusual information as inbound gliders.
Jottrand then heard gunfire below him along the canal as Belgian forces engaged the silent, dark gliders descending upon them. At this point, Jottrand and his men could also see the gliders, though Eben Emael’s antiaircraft batteries remained silent. Headquarters urgently inquired as to why no fire was coming from the fort. The officer in charge of antiaircraft stated the aircraft were not Belgian, but he could not confirm their identity. Headquarters issued a terse command: “Well then, shoot! Goddamn it, shoot!”
Events at the Bridges
Gliders descended on the canal bridges despite Jottrand’s order to blow the Canne bridge. After issuing the order a second time, the Canne bridge was destroyed, halting Schaechter’s platoon. Altman’s platoon captured the Veldwezelt bridge intact, using a hollow charge to disable the primary defensive casemate.
Oberleutnant Schacht’s platoon attacked the Vroenhoven bridge, swiftly overwhelming the defenders. They secured the bridge and disabled the demolition charges before they could be activated. Koch’s group established radio communication with the dispersed German forces. Belgian resistance around the bridges collapsed within three hours.
Two bridges were now usable by the Germans. Luftwaffe Stuka dive-bombers had eliminated the sector commander responsible for signaling the detonations, destroying his headquarters and killing him along with 20 others.
Fallschirmjäger pioneers used inflatable rafts to cross the Albert Canal. Their objective was to use flamethrowers and explosives in their assault on Eben Emael.
German forces landed gliders on the grassy surface of the fortress. Immediately, teams of raiders began their meticulously planned disabling of the Belgian defenses. Machine-gun positions were neutralized with grenades, while observation points were obscured with small arms fire.
Specialized, shaped explosive charges, known as “hohlladungen”, were placed against the armored casemates and cupolas. When detonated, the effects proved devastating. Entryways were destroyed, weapons damaged or displaced, and the crews within either killed or severely wounded.
This pattern was systematically carried out across the Eben Emael fortress. Gun crews were eliminated and their positions were captured or rendered inoperable. Belgian forces found themselves fighting for survival rather than defending their strategic position.
The Assault on Eben Emael
Assault teams moved systematically, taking out the fort’s observation posts and artillery emplacements. Paratroopers established defensive positions with machine guns, firing on Belgian infantry forces moving towards them. The attackers came under intense fire from Belgian artillery positioned within a run-down building on the fort’s north side, as well as Casemate No. 23, which continued to fire its 75mm gun despite a damaging blow from a hollow charge. The Belgians stubbornly maintained their fire even as heavy weapons forced German troops to seek cover.
As German soldiers pushed towards the canal, the commander of the Belgian 120mm guns awaited instructions to target the Vroenhoven bridge. After a delay, the command came at roughly 10:30, but only a single shot was fired. A German demolition charge was placed in the gun tubes, its explosion filling the air with smoke. Despite the fumes choking the fortress, some Belgian casemates continued to resist.
The German assault faced significant obstacles. Within the first fifteen minutes, two soldiers were killed, and eight others were severely injured. This drastically reduced their numbers, leaving only 62 to confront the defenders of Eben Emael. Though many Belgians were contained within the fort, the Germans remained wary of potential counterattacks from hidden positions.
Under Attack
Heavy Belgian artillery fire rained down on Fort Eben Emael; the threat of a Belgian infantry counterattack loomed heavily. In the absence of Oberleutnant Witzig, Lieutenant Delica, a Luftwaffe liaison officer, held a tenuous position on the southern end of the fort. Wenzel maintained command and directed Stuka divebombers to suppress the remaining Belgian resistance. Around 0830, amidst the chaos, Witzig arrived by glider.
Inside Eben Emael, Major Jottrand attempted to organize counterattacks, but his troops were primarily gunners, not trained infantry units. His call for volunteers met with little enthusiasm, and the resulting efforts were ineffective. A subsequent attempt, utilizing an infantry detachment from a neighboring position, suffered from unfamiliarity with the fort’s layout and collapsed under repeated Stuka air assaults. Similarly, a second sortie by the garrison, poorly equipped for infantry combat, also faltered.
In the early afternoon, a Belgian force of approximately 200 men from the village of Wonck initiated a counterattack. Divebombers shattered the advance, with roughly half the Belgian force eventually seeking refuge within Eben Emael. They could not be persuaded to participate in further actions outside the fort. Though some defensive positions within the fort remained active, this marked a turning point in the battle.
As darkness descended, the surviving garrison of Eben Emael sought what safety they could underground, barricaded behind fortifications. The German paratroopers maintained control of the surface, enduring harassing fire from Belgian artillery. For the moment, the garrison was safe, but any hope of counterattack seemed increasingly unlikely amidst the lingering threat of renewed German assault.
Across the Canal and Closing In
A massive explosion shook Eben Emael at 0200. The defenders, anticipating a German infantry attack, opened fire into the darkness from their remaining positions. No assault came, but in the concealing gloom, German paratroopers silenced two of the remaining 75mm guns with explosives. A single turret continued to fire throughout the night, targeting German units across the Meuse and those positioned on the fort itself. Though this resistance was a persistent irritant, it could not alter the fort’s fate – the key gun emplacements capable of targeting the bridges were now out of action.
Throughout the afternoon and night of May 10th, German engineers made repeated attempts to cross the canal in assault boats. These efforts were consistently repelled by Belgian fire, particularly from Eben Emael’s Casemate No. 13. Finally, late at night, the engineers successfully established a foothold across the canal and united with the paratroopers atop the fort. Using demolition charges, they silenced Casemate No. 13.
The fort’s defenders were forced to retreat deeper into the tunnels as the Germans relentlessly breached Belgian positions with grenades, demolition charges, and gunfire. Attackers also infiltrated the fortress, dismantling the defenders’ sandbag barricades. They were joined by German infantry who had joined the forces on the fort and by tank units advancing from across the canal.
By 1000 on May 11th, the fort’s defenses were severely compromised. Debris and the wounded filled the corridors, along with fumes of chlorine gas from ruptured sanitation barrels. The compromised air conditioning forced defenders in some areas to wear gas masks. Though some soldiers continued a valiant resistance, morale within the fort was collapsing.
The Fall of Eben Emael
Major Jottrand, commander of Fort Eben Emael, repeatedly contacted his superiors for orders. He received instructions to destroy the fort, either completely or after evacuating his men. If unable to destroy the fort, his orders were to destroy it along with the remaining garrison.
Jottrand convened his remaining officers and lead NCO. All agreed that surrender was necessary. He attempted to inspire his troops with a plan for a breakout attempt but found them unwilling. Jottrand again contacted higher command but received the same instructions: Eben Emael must not surrender, it must be destroyed.
Jottrand sent an officer to begin surrender negotiations with the Germans while ensuring the destruction of the fort’s remaining equipment. At approximately 12:15, a bugle sounded the surrender call repeatedly. The Belgian garrison emerged under a flag of truce and was taken prisoner.
A German officer questioned Jottrand regarding any remaining explosives. Jottrand assured him there were none. The battle for Fort Eben Emael, lasting roughly 30 hours, was concluded.
Koch After the War
After its involvement in the attack on Eben Emael, Koch’s unit was disbanded. Now promoted to major, Koch took part in the airborne assault on Crete. This battle became a turning point for the German airborne forces, resulting in significant losses. Witzig and Wenzel, who participated in the Eben Emael raid, also fought on Crete, this time as paratroopers.
Witzig continued to serve in Russia and later rose to the rank of colonel in the postwar German Army. Wenzel was commissioned as an officer, reaching the rank of captain before being captured by American forces in North Africa. After the war, he returned home and became an Oberjaeger (a professional forester).
Major Koch did not survive the war. He was known for his love of fast cars, and in 1942, he died in an automobile accident on the autobahn when his roadster collided with a truck.
Today, the fortress of Eben Emael stands as a historical site. The Eben Emael Association offers guided tours and maintains a museum. Visitors can explore the silent casemates and bunkers, learning about the events that took place there in May of 1941.
