In 1928, Nikola Tesla received patents for an apparatus for aerial transportation. It is one of the earliest example of VTOL aircraft. In the late 1950s and early 1960s almost all fighter aircraft designed included some VTOL features. This was a response to the worrying possibility that a first-strike against airfields by nuclear armed bombers would leave a country open to attack by following bombers. The "solution" was to use VTOL fighters that could be moved to open fields around the countryside, making them immune to widespread destruction.
In reality the costs of VTOL performance were huge, and while it turned out to be fairly easy to move the plane, moving the support equipment and fuel was not so easy. By the mid-1960s interest in VTOL had faded, perhaps due much to the widespread introduction of ICBMs as the main nuclear delivery system.
Currently there are believed to be two types of practical VTOL aircraft in operation:
The Harrier is often flown in STOVL mode which enables it to carry a higher fuel or weapon load over a given distance. It was developed from the Hawker P.1127 and Kestrel.
The United States Marine Corps uses a license-built derivative of the Harrier. NASA has flown other VTOL craft such as the XV-15 research craft, as have the Soviet Navy and West German Air Force. The Indian and Spanish Navies operate Sea Harriers, mainly from aircraft carriers.