Lion-class battlecruiser

Princess Royal at anchor, before 1916
Class overview
Builders:	HM Dockyard, Devonport Vickers, Barrow-in-Furness
Operators:	Royal Navy
Preceded by:	Indefatigable class
Succeeded by:	Queen Mary
Built:	1910–1912
In commission:	1912–1920
Completed:	2
Scrapped:	2
General characteristics (as built)
Type:	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 6.75 in (27.0 m)
Draught:	32 ft 5 in (9.9 m) at deep load
Installed power:	70,000 shp (52,000 kW) 42 × Yarrow boilers
Propulsion:	4 × shafts; 2 × steam turbine sets
Speed:	27.5 knots (50.9 km/h; 31.6 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-inch (343 mm) guns 16 × single 4-inch (102 mm) guns 2 × 21-inch (533 mm) torpedo tubes
Armour:	Belt: 9–4 inches (229–102 mm) Bulkheads: 4 inches (102 mm) Barbettes: 9–8 inches (229–203 mm) Turrets: 9 inches (229 mm) Decks: 2.5 inches (64 mm) Conning tower: 10 inches (254 mm)

The Lion class were a pair of battlecruisers built for the Royal Navy before World War I. Nicknamed the "Splendid Cats", the ships were a significant improvement over their predecessors of the Indefatigable class in terms of speed, armament and armour. These improvements were in response to the German battlecruisers of the Moltke class, which were in turn larger and more powerful than the first British battlecruisers of the Invincible class.

Lion served as the flagship of the Grand Fleet's battlecruisers throughout World War I. She sank the German light cruiser Cöln during the Battle of Heligoland Bight in August 1914 and participated in the battles of Dogger Bank in 1915 and Jutland the following year. She was so badly damaged at the Battle of Dogger Bank that she had to be towed back to port. During the Battle of Jutland, Lion suffered a serious cordite fire that could have destroyed the ship.

Princess Royal also participated in the Battle of Heligoland Bight and was then sent south to the Caribbean to intercept the German East Asia Squadron in case they used the Panama Canal. After the squadron was sunk at the Battle of the Falkland Islands in December 1914, Princess Royal rejoined the 1st Battlecruiser Squadron (BCS). During the Battle of Dogger Bank, she scored only a few hits; one crippled the German armoured cruiser Blücher which allowed the enemy vessel to be caught and sunk by the concentrated fire of the British battlecruisers. Shortly afterwards, Princess Royal became the flagship of the 1st BCS and participated in the Battle of Jutland. Both ships were present during the inconclusive Action of 19 August 1916.