Leonardo Da Vinci, while primarily an artist, created the basic concepts for many inventions that have since been realized, such as the helicopter, the parachute, armored cars and even robots. While Da Vinci did have the initial ideas for many of these devices, he is often not credited with actually inventing them, as many were simply designs or blueprints that were never fully completed during his lifetime.
Da Vinci was fascinated with the idea of flight, and in addition to laying down the foundations of what would later become the helicopter (called the aerial screw by Da Vinci), he also conceived of a device that could carry a person into the air using wings.
While a long way from being an aeroplane, Da Vinci's device placed a person on a long flat frame with wings on either side that could be operated by the pilot. Despite his designs, he was aware that it would be impossible to generate enough power to get off the ground.
Da Vinci was also a military engineer, which led to many of his inventions being tailored for warfare. He conceived the idea of a multi-barreled cannon, as well as a giant crossbow - both ideas that went on to be further developed and implemented many years after his death.