The world's greatest navies continue to put faith, and resources, into carrier aviation.
Here's What You Need to Know: Aircraft carriers provide a unique combination of presence, prestige, and lethality.
The first true aircraft carriers entered service at the end of World War I, as the Royal Navy converted several of its excess warships into large, floating airfields. During the interwar period, Japan and the United States would make their own conversions, and all three navies would supplement these ships with purpose-built carriers. Within months of the beginning of hostilities in September 1939, the carrier demonstrated its worth in a variety of maritime tasks.