The Belgian sentries never heard them coming — because the aircraft had no engines.

The Gliders of Fort Eben-Emael: Belgium's 'Impregnable' Fortress Falls in Hours

How 78 German Paratroopers Achieved the Impossible on the First Day of the Blitz

78 German glider troops landed atop 'impregnable' Fort Eben-Emael and defeated 1,200 defenders in hours.

The Belgian sentries never heard them coming. At 4:25 a.m. on May 10, 1940, nine DFS 230 gliders descended silently through the pre-dawn darkness over the Meuse Valley, their tow ropes cut miles back over German territory. Inside, 78 elite Fallschirmjäger of Sturmgruppe Granite gripped their weapons and the strange cylindrical charges that would change fortress warfare forever.

Fort Eben-Emael was supposed to be invincible. Carved into the limestone heights overlooking the Albert Canal, this massive fortification housed 1,200 Belgian troops behind walls of reinforced concrete up to 2.5 meters thick. Its armored cupolas contained 120mm guns capable of destroying any bridge within range — bridges Hitler desperately needed intact for his armored thrust into France. Military observers called it the strongest fortress in Europe.

But German intelligence had been watching. For months, Hauptmann Walter Koch's men had trained on a replica fortress in Czechoslovakia, practicing with a revolutionary new weapon: the Hohlladung, or shaped charge. These 50-kilogram explosive devices focused their blast into a superheated jet capable of punching through steel and concrete like a blowtorch throu…

💡 The shaped charges used at Eben-Emael were so secret that German soldiers were forbidden to discuss them, and Allied intelligence didn't fully understand what had happened until captured examples were examined in 1945.