How a glider assault on a flat roof doomed the Allied defense of Belgium
In May 1940, Germany launched a lightning invasion of Belgium, bypassing static defenses with a daring airborne strike on Fort Eben-Emael. While Allied commanders expected a repeat of the First World War, German forces executed a revolutionary breakthrough through the Ardennes, encircling the Allied armies in just five days.
The German invasion, known as Fall Gelb, began on 10 May 1940. While Allied forces committed their best divisions to the Dyle Line in central Belgium—expecting the main German thrust there—the Wehrmacht enacted a secondary, decisive phase. Using the Ardennes region, which the Allies deemed impassable, German Panzer divisions raced toward the English Channel. This maneuver effectively cut off the Allied armies from their supply lines in northern France, forcing a desperate retreat to the coast.
A critical component of the German success was the neutralization of Fort Eben-Emael. Recognizing that the fort’s flat, unprotected roof was a vulnerability, Adolf Hitler ordered a specialized airborne operation. On 10 May, German paratroopers landed gliders directly onto the fort’s surface. Using 50-kilogram hollow-charge explosives, they disabled the heavy gun turrets that guarded the Albert Canal bridges. This allowed German ground forces to bypass the primary defensive barriers, rendering the Belgian strategy of static resistance obsolete.
The Belgian military, despite possessing capable anti-tank weaponry like the 47 mm FRC gun, was hampered by political divisions and a lack of modern air power. With only 118 serviceable aircraft on the day of the invasion, the Belgian Air Force could not contest the skies. By 28 May 1940, the Belgian Army surrendered. The subsequent evacuation of Allied forces from Belgian ports during Operation Dynamo allowed many to escape, but the collapse of the Belgian front left the continent open to German occupation until 1944.
