Merville Battery was designed to cover the mouth of the River Orne.

It posed a threat to Sword Beach and the British 3rd Dvision.

It was left to the men of the British 9th Parachute Battalion (commanded by Col. Otway) to take the battery.

This feat was achieved with a force of only 150 men, one machine gun and a few lengths of Bangalore Torpedo (used to destroy barbed-wire fences).

FURTHER INFORMATION
http://en.wikipedia.org/wiki/Merville_Battery