When we think about art, the first thing that generally springs to mind are the masterworks of the Renaissance period, when men such as Leonardo da Vinci, Michelangelo, and other Teenage Mutant Ninja Turtles defined the visual arts for the next five centuries and counting. Painting, sculpture, and the other forms practiced by these masters had a long history even before their time, however, and have helped define capital-A Art since antiquity.