Timeline for aircraft carrier service
Aircraft carriers have their origins during the days of World War I. The earliest experiments consisted of fitting temporary "flying off" platforms to the gun turrets of the warships of several nations, notably the United States and the United Kingdom. The first ship to be modified with a permanent flight deck was the battlecruiser HMS Furious, which initially had a single flying-off deck forward of the original superstructure.
Source: Wikipedia — Timeline for aircraft carrier service (CC BY-SA 4.0)