A look back at a time when battleships ruled the waves - huge monsters of steel, costing millions and protected by massive belts of armour. The advent of the aeroplane with small low-cost weaponry that could only not disable these leviathans but sink them altogether meant that suddenly these giant weapons of war were vulnerable in a way never predicted by their original designers. This programme recalls the loss of HMS Hood and Bismarck, the attack on Pearl Harbor, and the sinking of the HMS Prince of Wales.