HMS Glorious was the second of the three Courageous-class battlecruisers built for the Royal Navy during the First World War. Designed to support the Baltic Project championed by the First Sea Lord, Lord Fisher, they were relatively lightly armed and armoured. Glorious was completed in late 1916 and spent the war patrolling the North Sea. She participated in the Second Battle of Heligoland Bight in November 1917 and was present when the German High Seas Fleet surrendered a year later.

Glorious was paid off after the war, but was rebuilt as an aircraft carrier during the late 1920s. She could carry 30 per cent more aircraft than her half-sister Furious which had a similar tonnage. After re-commissioning in 1930, she spent most of her career operating in the Mediterranean Sea. After the start of the Second World War in 1939, Glorious spent the rest of the year hunting for the commerce-raiding German cruiser Admiral Graf Spee in the Indian Ocean before returning to the Mediterranean. She was recalled home in April 1940 to support operations in Norway. While evacuating British aircraft from Norway in June, the ship was sunk by the German battleships Scharnhorst and Gneisenau in the North Sea with the loss of over 1,200 lives.

During the First World War, Admiral Fisher was prevented from ordering an improved version of the preceding Renown-class battlecruisers by a wartime restriction that banned construction of ships larger than light cruisers. To obtain ships suitable for traditional battlecruiser roles, such as scouting for fleets and hunting enemy raiders, he settled on a design with the minimal armour of a light cruiser and the armament of a battlecruiser. He justified their existence by claiming he needed fast, shallow-draught ships for his Baltic Project, a plan to invade Germany via its Baltic coast.

Glorious had an overall length of 786 feet 9 inches (239.8 m), a beam of 81 feet (24.7 m), and a draught of 25 feet 10 inches (7.9 m) at deep load. She displaced 19,180 long tons (19,490 t) at load and 22,560 long tons (22,922 t) at deep load. Glorious and her sisters were the first large warships in the Royal Navy to have geared steam turbines. The Parsons turbines were powered by eighteen Yarrow boilers. During the ship's abbreviated sea trials, she reached 31.42 knots (58.19 km/h; 36.16 mph). The ship was designed to normally carry 750 long tons (760 t) of fuel oil, but could carry a maximum of 3,160 long tons (3,210 t). At full capacity, she could steam for an estimated 6,000 nautical miles (11,110 km; 6,900 mi) at 20 knots (37 km/h; 23 mph).

Glorious carried four BL 15-inch (381 mm) Mark I guns in two twin-gun turrets, one each fore ('A') and aft ('Y'). Her secondary armament was 18 BL 4-inch (102 mm) Mark IX guns mounted in six triple mounts. These mounts had the three breeches too close together and the 23 loaders tended to interfere with one another. This negated the mount's intended high rate of fire against torpedo boats and other smaller craft. A pair of QF 3-inch (76 mm) 20 cwt anti-aircraft guns were fitted abreast of the mainmast on Glorious. She mounted two submerged tubes for 21-inch torpedoes and 10 torpedoes were carried.

Glorious' keel was laid down on 1 May 1915 by Harland and Wolff at their Belfast shipyard. She was launched on 20 April 1916 and completed on 14 October at a cost of £1,967,223. During her sea trials the following month, her sister Courageous sustained structural damage while running at full speed in a rough head sea and had the damaged areas stiffened shortly afterwards to prevent a recurrence. Glorious did not suffer similar damage and did not receive her stiffening until 1918. Upon commissioning, Courageous served with the 3rd Light Cruiser Squadron of the Grand Fleet. After most of the 1st Cruiser Squadron was sunk at the Battle of Jutland, the squadron was re-formed with Courageous and Glorious. Glorious received six twin-tube torpedo mounts in mid-1917: one mount on each side of the mainmast on the upper deck and two mounts on each side of 'Y' turret on the quarterdeck.

On 16 October 1917 the Admiralty received word of German ship movements, possibly indicating some sort of raid. Admiral Beatty, commander of the Grand Fleet, ordered most of his light cruisers and destroyers to sea in an effort to locate the enemy ships. Courageous and Glorious were not initially ordered to sea, but were sent to reinforce the 2nd Light Cruiser Squadron patrolling the central part of the North Sea later that day. Two German Brummer-class light cruisers slipped through the gaps in the British patrols and destroyed a convoy bound for Norway during the morning of 17 October, but the British warships received no word of the engagement until that afternoon. The 1st Cruiser Squadron was ordered to intercept, but was unsuccessful as the German cruisers were faster than expected.

Throughout 1917 the Admiralty was becoming more concerned about German efforts to sweep paths through the British-laid minefields intended to restrict the actions of the High Seas Fleet and German submarines. A preliminary raid on German minesweeping forces on 31 October by light forces destroyed 10 small ships and the Admiralty decided on a larger operation to destroy the minesweepers and their light cruiser escorts. Based on intelligence reports, the Admiralty allocated the 1st Cruiser Squadron on 17 November 1917, with cover provided by the reinforced 1st Battlecruiser Squadron and distant cover by the battleships of the 1st Battle Squadron.