The rise of France's Second Empire, established by Louis Napoleon III in 1852, became associated with an architectural style that first appeared in an extension of the Louvre at the beginning of the new emperor's reign in France. Whereas the Italianate style, from which Second Empire borrowed much of its massing and details, was part of the Picturesque movement, the Second Empire style was considered thoroughly modern. Its defining feature was the Mansard roof, generally pierced with dormers, named after seventeenth-century French architect Francois Mansart.