The British Navy was bored. The British Army just won a “great” victory on the continent against the advancing Germans at Mons. (But they were forced to retreat when the French on their flank fell back, 250 miles.) The stalwart British Army was the talk of the court and newspapers, while the Navy… patrolled the North Sea.

On 25 August, 1914, two British commodores were sitting around over a glass of whiskey just thinking shit up, because that’s what field grade officers do when they’re bored. They devised a plan to ambush one of Germany’s destroyer flotillas. They would send three submarines to surface off of Heligoland Blght, deep in German territorial waters. German destroyers would have to respond. Waiting for them would be the commodores’ own destroyers and a few cruisers. It would be a cracking good time.

Three days later on the 28th, the submarines surfaced, were spotted, the Germans responded, and the British flotillas ambushed them. It went exactly as planned, except that the late summer North Sea fog reduced visibility to two miles. The clean and orderly “Crossing of the T” envisioned by the commodores turned into a melee in the fog, consisting of a dozen separate duels. The Germans immediately sortied a light cruiser force. The British risked losing the battle altogether.

Fortunately, there were other bored British naval officers. At a dinner party on the 26th, Adm Beatty heard of the plan from First Lord of the Admiralty, Winston Churchill, who just approved it. Beatty wanted in on some of the action too. He wired forward to Scapa Flow to get his ships ready, and then raced back to the port. But he didn’t tell anyone.

Just as the chaotic battle was beginning turn against the British, a beautiful sight emerged from the mist: Admiral Beatty’s six heavy cruisers and six big battlecruisers. Commodore Tyrwitt would remark “they looked like a line of elephants amidst a pack of wild dogs”. And the Germans, to continue the animal metaphors, “scattered like cockroaches”. In minutes the battle was over. The Germans had three cruisers and a destroyer sunk, and seven more ships heavily damaged, almost all by Beatty. And the British had one cruiser and two destroyers slightly damaged.

In an age of dozens upon dozens of giant dreadnaught battleships on each side, the Battle of Heligoland Bight, a very minor action by small ships, had outsized influence over the war. As the British celebrated, Kaiser Wilhelm was convinced by the battle that the British could not be defeated at sea, and ordered that the German High Seas Fleet be kept in port except by his express permission. The war at sea from then on would be fought by German U-Boats and not by German battleships.