Grand Fleet and High Seas Fleet

The Grand Fleet was formed in August 1914 from the ships of the Home Fleets; it was commanded by Admiral John Jellicoe and, from November 1916, by David Beatty. It counted several dozen dreadnoughts and battlecruisers, and from late 1917 a squadron of American battleships served with it. Its presence at Scapa Flow barred the German fleet's way to the ocean and made the blockade of Germany possible.

The High Seas Fleet, so named in 1907, was built up by Kaiser Wilhelm II and Admiral Alfred von Tirpitz to challenge the Royal Navy. Weaker in numbers, it tried to trap parts of the British fleet, which led to the battles of the Dogger Bank and Jutland. Afterwards it rarely put to sea, and in autumn 1918 a mutiny of its sailors set off the revolution in Germany. After the armistice it was interned at Scapa Flow, where its crews scuttled the ships in June 1919.