The Lord Nelson class consisted of a pair of pre-dreadnought battleships built for the Royal Navy in the first decade of the twentieth century.

They remained there after the end of that campaign in 1916 and were assigned to the Eastern Mediterranean Squadron, which was later redesignated the Aegean Squadron, to prevent the ex-German battlecruiser Yavuz Sultan Selim and her consort, the light cruiser Midilli, from breaking out into the Mediterranean from the Dardanelles, although neither ship was present when the German ships made that attempt in early 1918.

Pioneering naval gunnery developments by Captain Percy Scott in the early 1900s were already pushing expected battle ranges out to an unprecedented 6,000 yards (5,500 m), a distance great enough to force gunners to wait for the shells to arrive before applying corrections for the next salvo.

Another problem was that longer-range torpedoes were expected to soon be in service and these would discourage ships from closing to ranges where the smaller guns' faster rate of fire would become preeminent.

Keeping the range open generally negated the threat from torpedoes and further reinforced the need for heavy guns of a uniform calibre.

[2] The Board of Admiralty wished to keep the size of the 1903–1904 Naval Programme battleships to about the 14,000 long tons (14,000 t) of the earlier Duncan class and also required them to be able to use the drydocks at Chatham, Portsmouth and Devonport, even though these had been enlarged before the ships were completed.

Preliminary design work began in mid-1902 and it became clear that a displacement at least equal to that of the preceding King Edward VII class would be required.

[3] The Admiralty formally approved a 16,350-long-ton (16,610 t) design armed with four 12-inch and a dozen 9.2-inch guns on 6 August 1903, but revoked it in October when they discovered that it could not be docked at Chatham.

Watts refined the design to ensure that it could enter the Chatham docks, which required reducing the number of 9.2-inch guns to only 10, and it was approved on 10 February 1904.

[6] The Lord Nelson class "proved good seaboats and steady gun platforms, with excellent manoeuvrabiling qualities.

The Lord Nelsons were the first British battleships to be built with fuel oil sprayers to increase the burn rate of the coal.

[9] The main armament of the Lord Nelson-class ships consisted of four 45-calibre breech-loading (BL) 12-inch Mark X guns in a pair of twin-gun turrets, one each fore and aft of the superstructure.

[8] For defence against torpedo boats, the ships carried two dozen 50-calibre quick-firing (QF) 12-pounder (3 in (76 mm)) 18 cwt guns[Note 1] in single mounts in the superstructure.

The waterline main belt was composed of Krupp cemented armour (KCA) 12-inches thick, although it thinned to 6 inches (152 mm) at its lower edge.

The Lord Nelsons were the first British ships fitted with unpierced watertight bulkheads for all main compartments with access gained by using lifts.

[20] Early in 1919 the Admiralty decided that the Navy needed a radio-controlled target ship to properly train gunnery officers.

At an equivalent range of 25,230 yards (23,070 m), the plates were completely destroyed and the Admiralty realized that 15-inch shells would do much the same to any of the surplus early dreadnoughts.

Lord Nelson became flagship of the vice-admiral commanding the Nore Division of the Home Fleet at the beginning of 1909, but became a private ship in early 1914.

Both ships were transferred to the Mediterranean in 1915 to support Allied forces in the Dardanelles Campaign and to help blockade the German battlecruiser Goeben.

After the evacuation of Gallipoli at the beginning of 1916 they were assigned to the Eastern Mediterranean Squadron which was tasked to guard against a breakout attempt by Goeben and Breslau, now transferred to the Ottoman Navy and renamed Yavûz Sultân Selîm and Mdilli, respectively, support the Allied forces in the Macedonian front and defend the various Greek islands occupied by the Allies.

While heading towards Mudros, the ships entered a minefield; Midilli sank after striking multiple mines and Yavuz Sultan Selim struck several, but was able to withdraw back to the Dardanelles.

[23] On 30 October 1918 the Ottoman Empire signed the Armistice of Mudros on board Agamemnon and she participated in the occupation of Constantinople the following month.