When Vasari wrote his enormously influential book, Lives of the Artists, in the 16th century, he credited Giotto, the Late Gothic artist, with being the first artist to leave behind the medieval practice of painting what one knows and believes, for painting what what one sees. This interest in the natural world is a key feature of the Renaissance, which begins in the 15th century in both Italy and northern Europe. In the 1500s, the Renaissance is interrupted by the Protestant Reformation, a period of tremendous violence and upheaval. In the aftermath of the Reformation and Counter-Reformation, during the Baroque era (1600s), artists such as Bernini, Caravaggio, Rubens, Velazquez and Rembrandt were masters of drama, light and illusion. And in the 18th century, the artists Watteau, Boucher, and Fragonard typify the aristocratic style known as Rococo. Not long after, Jacques Louis David invented a style reflecting Enlightenment ideas by looking back to ancient art. He became a revolutionary and 1st painter to Napoleon, and ushered in what is sometimes considered to be the beginnings of modern art.