The first HMS Hermes (1923) was the first purpose built fleet aircraft carrier of the Royal Navy, built just after the First World War. The ship was laid down at Armstrong-Whitworth in January 1918 and launched on September 11, 1919. She was not commissioned until 1923. The design was not inspired by practical experience, in operation her air complement was small, her protection and endurance limited and her stability was poor, especially in high seas. During WW II she served briefly with the Home Fleet before being assigned to the southern Atlantic from October 1939. She worked with the French navy based at Dakar until the Vichy government came to power, following that her aircraft took part in a strike against the French vessels at Dakar. In July 1940 she collided with a merchant vessel and was repaired at Simonstown, South Africa. Following repairs she continued patrols but this time in the Indian Ocean. She was sunk off Batticaloa, Ceylon during an attack by Japanese aircraft on April 9, 1942 while escorting a convoy from Ceylon to the Maldives, two other naval vessels and two tankers were also sunk.

Displacement: 11,085 tons
Crew: 700
Length: 182.27 m
Beam: 21.41 m
Draught: 5.64 m
Propulsion: Two steam turbines, 40,000 shp
Speed: 25 Knots
Armament: Six 13.97 cm guns, three 10.16 cm AA guns and eight 12.7 mm AA guns. Six 20 mm guns were added in 1934.
Aircraft: Initially 15 (Fairey III and Flycatcher) then 12 (Fairey Swordfish II or Walrus).