Leonardo's greatest work in the 14/1500's. A lot of his inventions can be attributed to working for the military as an engineer. Da Vinci is probably the most famous Italian to ever live.
http://www.ranker.com/list/leonardo-da-vinci-and-_39_s-greatest-art-and-inventions-and-theories/stokified,
Lady with an Ermine
Reversible Crank Mechanisms
Calculator
Robotic Knight (Cyborg)
Tank
Giant Crossbow
Theory of Plate Tectonics and the Double Hull
De Divina Proportione (mathematical Proportion in Art)
Viola Organista (musical Instrument)
Ball Bearing