List of monitors of the Royal Navy
This is a list of monitors of the Royal Navy of the United Kingdom. Section::::"Humber"-class. The "Humber"-class monitors were three river monitors under construction for the Brazilian Navy in Britain in 1913, all three were taken over by the Royal Navy shortly before the outbreak of the First World War and were commissioned as small monitors, seeing extensive service during the war. Section::::"Abercrombie"-class. The "Abercrombie"-class monitors came about when Bethlehem Steel in the United States, the contracted supplier of the main armament for the Greek battleship being built in Germany, instead offered to  sell the four 14"/45 caliber gun twin gun turrets to the Royal Navy on 3 November 1914, the ships were laid down and launched within six months, seeing service throughout the war. Section::::"Lord Clive"-class. The Lord Clive"-class monitors, sometimes referred to as the General Wolfe"-class, were built to meet the need for more shore bombardment ships, using twin gun turrets taken from decommissioned "Majestic"-class pre-dreadnought battleships. Three of the ships, HMS "General Wolfe", "Lord Clive" and "Prince Eugene", were converted to take the BL 18 inch Mk I naval gun that had originally been allocated to . Section::::"Marshal Ney"-class. The  Marshal Ney-class monitors were built to use the two modern 15-inch turrets made available by the redesign of and as battlecruisers. Section::::"Gorgon"-class. The "Gorgon"-class monitors were originally built as coastal defence ships for the Royal Norwegian Navy, but requisitioned for British use. Section::::"M15"-class. The "M15"-class monitors were fourteen ships ordered in March 1915, as part of the War Emergency Programme of ship construction, mounting 9.2 inch Mk VI gun turrets removed from the and the Mk X turrets held in stock for the and s. Section::::"M29"-class. The "M29"-class monitors were five ships ordered in March 1915, as part of  the War Emergency Programme of ship construction. Section::::"Erebus"-class. The "Erebus"-class monitors were two ships mounting a single twin BL 15 inch Mk I naval gun turret. They saw active service in World War I off the Belgian coast, were placed in reserve between the wars then served in World War II, with "Terror" being lost in 1941 and "Erebus" surviving to be scrapped in 1946. Section::::"Roberts"-class. The "Roberts"-class monitors were two ships mounting a single twin BL 15 inch Mk I naval gun turret built during the Second World War, featuring shallow draught for operating inshore, broad beam to give  stability and a high observation platform to observe fall of shot.