HMS Queen Mary was the last battlecruiser built by the Royal Navy before the First World War. The sole member of her class, Queen Mary shared many features with the Lion-class battlecruisers, including her eight 13.5-inch (343 mm) guns. She was completed in 1913 and participated in the Battle of Heligoland Bight as part of the Grand Fleet in 1914. Like most of the modern British battlecruisers, the ship never left the North Sea during the war. As part of the 1st Battlecruiser Squadron, Queen Mary attempted to intercept a German force that bombarded the North Sea coast of England in December 1914, but was unsuccessful. The ship was refitting in early 1915 and missed the Battle of Dogger Bank in January, but participated in the largest fleet action of the war, the Battle of Jutland in mid-1916. She was hit twice by the German battlecruiser Derfflinger during the early part of the battle and her magazines exploded shortly afterwards, sinking the ship.
Her wreck was discovered in 1991 and rests in pieces, some of which are upside down, on the floor of the North Sea. Queen Mary is designated as a protected place under the Protection of Military Remains Act 1986 as it is the grave of 1,266 officers and ratings.