François-Joseph Bélanger's career as a prominent architect and designer in the 1700s was assisted by a series of important patrons and well-connected friends. When he was only twenty, Bélanger was admitted to the prestigious Académie Royale d'Architecture under the protection of the connoisseur the comte de Caylus. In 1767 he was appointed the court's dessinateur des Menus Plaisirs (Designer of Entertainments). He rose to become its director ten years later, as well as premier architecte (first architect) to the comte d'Artois, brother of Louis XVI. Bélanger produced designs for important royal ceremonies, including the funeral of Louis XV, Louis XVI's coronation coach, and a jewel cabinet for Marie-Antoinette, one of the first major works in the Neoclassical style.
Despite his numerous royal connections, Bélanger supported the ideals of the French Revolution. Nonetheless, he was imprisoned for six months in 1794. When the monarchy was restored in 1814, he was employed again to design the royal ceremonies and a new official French seal.