The Grand Fleet was the main fleet of the British Royal Navy during the First World War.

It was formed in August 1914 from the First Fleet and elements of the Second Fleet of the Home Fleets and it included 35-40 state-of-the-art capital ships. It was initially commanded by Admiral Sir John Jellicoe. He was succeeded by Admiral Sir David Beatty in 1916.

The Grand Fleet was based first on Scapa Flow in the Orkney Islands and later at Rosyth on the Firth of Forth and only took part in one fleet action during the war - the indecisive Battle of Jutland.

After the war the Grand Fleet was disbanded with much of its strength forming a new Atlantic Fleet.

Not all the Grand Fleet was available to put to sea at any one time, because ships required maintenance and repairs. For a list of ships which were present at the Battle of Jutland in May 1916 see the article, Order of battle at Jutland. A number of others missed the battle for one reason or another. 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. This led to a slowly less cautious approach to the war as the strength increased. The fleet was at its weakest at the start of the war, when it was also least experienced at this sort of warfare and a number of minor but embarrassing losses occurred because of this inexperience. 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.

Claude Stanley Choules (pronounced /ˈʃuːlz/; 3 March 1901 – 5 May 2011) was the last World War I combat veteran, and was the last military witness to the scuttling of the German fleet in Scapa Flow. He was also the last veteran to have served in both world wars, and the last seaman from the First World War. At the time of his death, he was also the third oldest verified military veteran in the world and the oldest known living man in Australia. He was the seventh-oldest living man in the world. Choules became the oldest man born in the United Kingdom following the death of Stanley Lucas on 21 June 2010. Choules died in Perth, Western Australia, at the age of 110. He had been the oldest British-born man; following his death, that honour went to the Reverend Reginald Dean (born November 1902). In December 2011, the landing ship HMAS Choules was named after him, only the second vessel named after a sailor.

Claude Choules was born in Pershore,Worcestershire, on 3 March 1901 and raised in nearby Wyre Piddle. The son of Harry and Madeline (née Winn), Claude was one of seven children, although two died in early childhood. The surviving siblings were Douglas, Leslie, Phyllis, and Gwendoline. His mother left home when Claude was five, returning to the stage as an actress, and he and his older brothers were raised by his father. His older sister Phyllis lived with the family of a paternal uncle, while his younger sister Gwendoline was adopted by the family of a paternal aunt. Both Claude and his older brothers went to Pershore National Boys' School (see national school), though Douglas (born 1893) and Leslie (born 1894) emigrated to Western Australia in 1911.

Hugo von Pohl (August 25, 1855 – 23 February 1916) was a German admiral who during the First World War commanded the German High Seas Fleet from 1915 until shortly before his death from illness in 1916.

Pohl was born in Breslau (Wrocław), Prussian Silesia. He entered the Kaiserliche Marine in 1876 at age 21. He rose rapidly through the ranks and by 1910 he was promoted to vice admiral and commandant of the I Marine Geschwader. In April 1913 Pohl became chief of the admiralty staff. Before World War I, he was appointed a Companion of the Order of the Bath.

When the First World War broke out Pohl became a proponent of the U-boat arm. After the battle of Dogger Bank, Pohl replaced Admiral Friedrich von Ingenohl as commander in chief of the High Seas Fleet. Two days after taking command, on February 4, 1915, Pohl gave the order to use unrestricted submarine warfare against the Allies. When he became ill, he was replaced as commander of the High Seas Fleet by Reinhard Scheer on January 23, 1916.

World War I (WWI), which was predominantly called the World War or the Great War from its occurrence until 1939 (World War II), and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918. It involved all the world's great powers, which were assembled in two opposing alliances: the Allies (based on the Triple Entente of the United Kingdom, France and Russia) and the Central Powers (originally centred around the Triple Alliance of Germany, Austria-Hungary and Italy; but, as Austria–Hungary had taken the offensive against the agreement, Italy did not enter into the war). These alliances both reorganised (Italy fought for the Allies), and expanded as more nations entered the war. Ultimately more than 70 million military personnel, including 60 million Europeans, were mobilised in one of the largest wars in history. More than 9 million combatants were killed, largely because of enormous increases in lethality of weapons, thanks to new technology, without corresponding improvements in protection or mobility. It was the sixth-deadliest conflict in world history, subsequently paving the way for various political changes such as revolutions in the nations involved.