The history of submarines covers the historical chronology and facts related to submarines, manned autonomous boats that operate underwater. It includes the history of "submersibles", which were designed primarily to operate on the surface, and midget submarines, but not unmanned underwater vehicles. In the 19th century torpedoes were launched from surface "torpedo boats" but these were susceptible to gunfire as they had to close to a short range to launch. There was a requirement for a "submarine torpedo boat" which was shortened to "submarine".