It was formed in August 1914 from the First Fleet and elements of the Second Fleet of the Home Fleets and it included 25–35 state-of-the-art capital ships. It was initially commanded by Admiral Sir John Jellicoe. He was succeeded by Admiral Sir David Beatty in December 1916.
The Grand Fleet was based first at Scapa Flow in the Orkney Islands and later at Rosyth on the Firth of Forth and took part in the biggest fleet action during the war – the Battle of Jutland – in June 1916.
Not all the Grand Fleet was available to put to sea at any one time, because ships required maintenance and repairs. At the time of the battle of Jutland in May 1916 it had 32 dreadnought and super-dreadnought battleships. Of these 28 were in the Order of battle at Jutland.
The actual strength of the fleet varied through the war as new ships were built and others were sunk, but the numbers steadily increased as the war progressed and the margin of superiority over the German fleet progressed with it. After the United States entered the war, United States Battleship Division Nine was attached to the Grand Fleet as the Sixth Battle Squadron, adding four, and later five, dreadnought battleships.