Jacques Ignace Hittorff or, in German, Jakob Ignaz Hittorff was a German-born French architect who combined advanced structural use of new materials, notably cast iron, with conservative Beaux-Arts classicism in a career that spanned the decades from the Restoration to the Second Empire.

Charles Percier was a neoclassical French architect, interior decorator and designer, who worked in a close partnership with Pierre François Léonard Fontaine, originally his friend from student days. For work undertaken from 1794 onward, trying to ascribe conceptions or details to one or other of them is fruitless; it is impossible to disentangle their cooperative efforts in this fashion. Together, Percier and Fontaine were inventors and major proponents of the rich, grand, consciously-archaeological versions of neoclassicism we recognise as Directoire style and Empire style.