The Merville Battery was a particularly heavily fortified position and one of the first places to be attacked by Allied forces during the Normandy Landings on D-Day. A British force under the command of Terence Otway succeeded in capturing this position, suffering heavy casualties.
The Merville Battery was composed of four 6-foot-thick (1.8 m) steel-reinforced concrete gun casemates, built by the Todt Organisation. Each was designed to protect First World War-vintage Czech-made leFH 14/19(t) 100 mm (3.93-inch) mountain howitzers, range: 8,400 m.
Other buildings on the site included a command bunker, a building to accommodate the men, and ammunition magazines. During a visit on 6 March 1944, to inspect the defences, Field Marshal Erwin Rommel ordered the builders to work faster, and by May 1944, the last two casemates were completed.
The battery was defended by a 20 mm anti-aircraft gun and several machine guns in 15 gun positions, all enclosed in an area 700 by 500 yards (640 by 460 m) surrounded by two barbed wire obstacles 15 feet (4.6 m) thick by 5 feet (1.5 m) high, which also acted as the exterior border for a 100-yard-deep (91 m) minefield. Another obstacle was an anti-tank ditch covering any approach from the nearby coast.
The 9th Parachute Battalion, part of the 3rd Parachute Brigade attached to 6th Airborne Division, was given the objective of destroying the battery. However, when the battalion arrived over Normandy, their parachute descent was dispersed over a large area, so instead of over 600 men, only 150 with no heavy weapons or equipment arrived at the battalion assembly point. Regardless, they pressed home their attack and succeeded in capturing the battery, only to discover that the guns were of a lower caliber than expected [Czech-manufacture 100mm]. However, these still had the range (over 8000 metres) to hit targets on Sword Beach and in Ouistreham. Using what explosives they had been able to recover, the surviving 75 men tried to disable the guns.
When the British paratroopers had withdrawn, two of the guns were put back into action by the Germans. Another attack the next day by British Commandos failed to recapture the battery, which remained under German control until 17 August, when the German Army started to withdraw from the area.