In 1906, HMS Dreadnought was launched. Described as a deadly fighting machine, it transformed the whole idea of warfare and sparked a dangerous arms race.
On 10 February 1906 the world's media gathered in Portsmouth to watch King Edward VII launch what he and his ministers knew would be a world-beating piece of British technology.
It was both an entrancing piece of high technology and a weapon of previously unimagined destructive power. What the king unveiled that day was the Royal Navy's newest warship - HMS Dreadnought.
At the time, Britain was a nation obsessed with the Navy. The Navy was at the centre of national life - politically powerful and a major cultural force as well, with images of the jolly sailor Jack Tar used to sell everything from cigarettes to postcards. The 100th anniversary of the Battle of Trafalgar just months earlier had served to remind anyone who doubted it of the Royal Navy's power, size and wild popularity.
So if the British public had come to expect their Navy to be world-beaters, they were delighted with Dreadnought, and eager to hear all about her.
There was plenty to hear, for Dreadnought, says John Roberts of the Museum of Naval Firepower, "really transformed naval warfare rather like the tank did on land warfare. In fact Dreadnought was described at the time as 'the most deadly fighting machine ever launched in the history of the world'".
Dreadnought brought together for the first time a series of technologies which had been developing over several years. Most important was her firepower. She was the first all big-gun battleship - with ten 12-inch guns. Each gun fired half-ton shells over 4ft tall and packed with high explosive. They weighed as much as a small car. Standing next to one today, it is easy to see how a single broadside could destroy an opponent - and do so at 10 miles' distance.
These great distances caused problems of their own - in controlling and directing the fire - and Dreadnought was one of the first ships fitted with new equipment to electrically transmit information to the gun turrets.
For potential enemies on the receiving end this was a terrifying prospect. Admiral Lord West, a former head of the Royal Navy, calls Dreadnought "a most devastating weapon of war, the most powerful thing in the world".
Potential adversaries would also have trouble outrunning her. New steam turbine engines gave her a maximum speed of about 25mph. They made her more reliable than previous ships, and able to sustain a higher speed for much longer.
But there was something else, too. Dreadnought had been built in just one year - a demonstration of British military-industrial might at a time when major battleships generally took several years to build. This, says Roberts, was an "enormous achievement which made the Germans sit up because their shipbuilding capability just could not match that".
At the time, Germany was already beginning to expand her navy, but Britain had an unassailable lead, with hundreds of ships deployed all around the world. That superiority meant that in a world where it wasn't possible to take a train to France or a flight to Spain, the Royal Navy was the bulwark of Britain's defence - and by protecting the world's trade routes the guarantor of her wealth, too.
Into this comfortable and comforting world, Dreadnought came like a bolt from the blue. On the one hand she demonstrated the Royal Navy's technical and industrial lead over the navies of new nations like Germany and the United States. But on the other, Dreadnought reset every navy almost to zero.
All previous battleships - including all of those in the Royal Navy - were now obsolescent, and would soon be known dismissively as "pre-Dreadnoughts".
Now anyone who could build enough Dreadnoughts could challenge the Royal Navy's pre-eminence. Couldn't they?
They certainly tried. The unveiling "set ablaze the big naval armament race with Germany, who was determined to keep up with us", says Roberts. "Once we'd launched Dreadnought, she had to have Dreadnoughts, and better Dreadnoughts, and as she built her Dreadnoughts we progressively had to build more, bigger, and more powerful Dreadnoughts."
Britain was soon joined by Germany, France, the US, Japan and Italy in building Dreadnoughts while Brazil and Turkey ordered theirs from British shipyards.
In Britain there was Dreadnought fever as the public clamoured for more shipbuilding and the Liberal government, caught trying to reduce naval spending, was forced on the defensive. One election meeting was disrupted by cries of "Dreadnought! Dreadnought! Dreadnought!".
"We want eight and we won't wait" was another popular cry as naval propagandists demanded that number of new ships. The result was hardly a surprise. As the Home Secretary, Winston Churchill, wryly noted: "The Admiralty had demanded six ships; the economists offered four; and we finally compromised on eight."
The reason for the fever was that the stakes for the UK were so high. Only the Royal Navy could ensure British security, and only the Royal Navy, by protecting trade routes, could ensure her prosperity.
No other major nation was so reliant on its navy for its wealth and security. Lord West describes the disparity: "For us, supremacy at sea was fundamental for our survival. For them it was just nice to have."
Ultimately Britain won the naval arms race with Germany several years before World War One, and in time Dreadnoughts were replaced by super-dreadnoughts - with even larger guns, faster engines and more armour.
Dreadnought and her successors went on to form the backbone of the Grand Fleet, described by Churchill, by then First Lord of the Admiralty as "the Crown Jewels" and at their assembly, prior to the outbreak of war as "the greatest assemblage of naval power ever witnessed in the history of the world".
Dreadnought herself was taken out of service shortly after WW1 and sold for scrap in the early 1920s. But by then she had wrought her revolution. Naval warfare had changed forever.