Well, let's see, they invented movable type printing, a calendar that was as accurate as the Gregorian but developed hundreds of years earlier, percussive cap drilling that was capable of the deepest wells in the early 19th century, paper currency, watertight compartments partitioning ships, dental fillings, dominoes, clockwork escapements, forensic entomology, multi-stage rocketry, pontoon bridges, toilet paper, electronic cigarettes, Non-invasive prenatal diagnostic testing for Down's Syndrome, Synthesis of crystalline bovine insulin, and I know it's cliche, but since you arbitrarily set the period at 1500 years I have to include gunpowder.