The decision to storm the German-held Normandy beaches was not taken on the spur of the moment. The invasion involved years of developing military technology which would ensure victory.
One of the main issues in designing an invasion plan was how to get Allied troops ashore as fast as possible. The successful Normandy landings were in part thanks to Hobart's Funnies - modified tanks which could overcome all kinds of potential difficulties.
These amphibious tanks, which were able to operate in water, allowed the Allies to mount armoured attacks as soon as they came ashore. Other modified tanks cleared paths through minefields, acted as bulldozers or removed concrete obstacles.
But such tanks were not enough to defeat Nazi Germany. Other 'hi-tech' weapons were developed and used before the invasion to damage and weaken the enemy.
The British tried but failed to destroy Germany's hydroelectric dams because nets were erected to protect them from conventional torpedoes. This led to the invention of the bouncing bomb, which, as the name suggests, could bounce across water to avoid obstacles like torpedo nets.
Using bouncing bombs, the British destroyed dams in Germany's Ruhr Valley, causing widespread flooding and destruction.