A heavy cruiser is a type of large warship which originated with the British Hawkins class during World War I. They entered service after the war. The Washington Naval Treaty of 1921 restricted heavy cruisers to 10,000 tons and 8-inch guns. As a result, major naval powers started to build heavy cruisers, usually armed with eight or ten 8-inch guns. In the 1930s several navies began to secretly flout the tonnage limits, with the ships of the German Admiral Hipper class reaching over 14,000 tons displacement. However by the mid '30s Britain, France and Italy had ceased building heavy cruisers. A weakness of heavy cruisers was usually too weak armour, caused by tonnage limits, not sufficient against heavy guns. The last heavy cruisers were built during World War II, and ultimately resulted in the Alaska class of "large cruiser" which were often erroneously referred to as battlecruisers because of their size and armament. The category fell out of use after World War II. Some existing heavy cruisers lasted until the 1970s, sometimes after conversion to guided missile cruisers (general hull symbol CG).

In the United States Navy, the term first came into official use in 1930, with hull classification symbol CA.

Many other nations built or possessed heavy cruisers in the period 1920-1945, namely Britain, Japan, France, Italy, Germany, USSR, Spain, and Australia. They played a similar role to that of armored cruisers 40 years earlier.

The only heavy cruiser in existence today is the museum ship USS Salem (1947).

Interestingly, the term "heavy cruiser" has seen a revival in military-oriented science fiction. In Star Trek, USS Enterprise and Enterprise-A were ostensibly of the Constitution class of heavy cruisers. In Babylon 5, Earthforce fields the Hyperion-class heavy cruiser. Many other science fiction universes boast classes of heavy cruisers among their warring factions, and the term seems to be a catchall for larger, heavily-armed warships. Many of these spaceborne heavy cruisers also carry squadrons of fighters, adding a carrier role to their intended mission profile.

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