The Glorious class aircraft carrier was a design born of necessity. HMS Glorious and HMS Courageous were originally classified as 'large light cruisers'. They were armed with 15-inch guns and were one of the most extreme expressions of the battlecruiser philosophy. The only example more extreme was their half-sister ship HMS Furious. The three acquired the derogatory nicknames Curious, Spurious and Outrageous.

Once it was clear that their original design did not work, thought was given to converting them to aircraft carriers. Although not purpose built ships of that type, they compared well with their contemporaries in the Royal Navy in that respect. By the time of World War II, they had been aircraft carriers for nearly 20 years and were approaching the end of their service lives. However, that conflict interrupted plans to replace them.

Courageous was one of the first British victims of the conflict. In the early days of the war, hunter-killer groups were formed around the fleet aircraft carriers to find and destroy U-boats. However, U-29 turned the tables and sank Courageous on 17 September 1939. Following a near miss with HMS Ark Royal, the fleet carriers were withdrawn from this duty.

Glorious did not survive much longer. The first major campaign of the war involving the Royal Navy took place around Norway. Glorious, in concert with Ark Royal, provided cover to British forces in the centre of Norway, until they were driven out by the Luftwaffe. Glorious then flew fighters off to the area around Narvik. However, even that place became untenable, and British forces were withdrawn. Glorious took Hurricanes on board to attempt to bring them back to the UK, since the type would shortly be desparately needed in the Battle of Britain. The Hurricanes were not designed to land on an aircraft carrier. Nevertheless, the squadron managed it.

On the way back across the North Sea, disaster struck. Glorious and its two escorting destroyers were found by Scharnhorst and Gniesenau of the Kriegsmarine. The German heavy ships sent all three British vessels to the bottom with most of their crews.