HMS Lion was a battlecruiser built for the Royal Navy in the 1910s. She was the lead ship of her class, which were nicknamed the "Splendid Cats".^[1] They were significant improvements over their predecessors of the Indefatigable class in terms of speed, armament and armour. This was in response to the first German battlecruisers, the Moltke class, which were very much larger and more powerful than the first British battlecruisers, the Invincible class.

Lion underway
History
United Kingdom
Name	Lion
Namesake	Lion
Ordered	1909–1910 Building Programme
Builder	HM Dockyard, Devonport
Laid down	29 November 1909
Launched	6 August 1910
Commissioned	4 June 1912
Decommissioned	30 May 1922
Fate	Sold for scrap, 31 January 1924
General characteristics (as built)
Class and type	Lion-class battlecruiser
Displacement	26,270 long tons (26,690 t) (normal) 30,820 long tons (31,310 t) (deep load)
Length	700 ft (213.4 m)
Beam	88 ft 7 in (27 m)
Draught	32 ft 5 in (9.9 m) at deep load
Installed power	42 Yarrow boilers 70,000 shp (52,000 kW)
Propulsion	4 × shafts; 2 × steam turbine sets
Speed	28 knots (52 km/h; 32 mph)
Range	5,610 nmi (10,390 km; 6,460 mi) at 10 knots (19 km/h; 12 mph)
Complement	1,092
Armament	4 × twin 13.5 in (343 mm) guns 16 × single 4 in (102 mm) guns 2 × 21 in (533 mm) torpedo tubes
Armour	Belt: 4–9 inches (102–229 mm) Bulkheads: 4 inches (102 mm) Barbettes: 8–9 inches (203–229 mm) Turrets: 9 inches (229 mm) Decks: 2.5 inches (64 mm) Conning tower: 10 inches (254 mm)

Lion served as the flagship of the Grand Fleet's battlecruisers throughout World War I, except when she was being refitted or under repair.^[2] She sank the German light cruiser Cöln during the Battle of Heligoland Bight and served as Vice-Admiral David Beatty's flagship at the battles of Dogger Bank and Jutland. She was so badly damaged at the first of these battles that she had to be towed back to port and was under repair for more than two months. During the Battle of Jutland she suffered a serious propellant fire that could have destroyed the ship had it not been for the bravery of Royal Marine Major Francis Harvey, the gun turret commander, who posthumously received the Victoria Cross for having ordered the magazine flooded. The fire destroyed one gun turret which had to be removed for rebuilding while she was under repair for several months. She spent the rest of the war on uneventful patrols in the North Sea, although she did provide distant cover during the Second Battle of Heligoland Bight in 1917. She was put into reserve in 1920 and sold for scrap in 1924 under the terms of the Washington Naval Treaty.