Becoming a master on March 1, 1746, Denis Masson was one of the most important Parisian clockmakers of the 18th century. He began as an ouvrier libre, then became a master in 1746, opening workshops successively in the Abbaye Saint-Germain-des-Prés, on the pont Notre-Dame in 1747 and in the rue Sainte-Avoye in 1778. He quickly gained fame among important Parisian connoisseurs of luxury horology, particularly for his clocks adorned with Saxon porcelain figures. Like most of the finest clockmakers of his day, Denis Masson worked with many of the best artisans of the time. He collaborated with the bronze caster Jean-Baptiste Vallée and the cabinetmakers Lieutaud and Foullet. Among his clients were the Infanta of Parma, the duchess de Mazarin and the duchess de Villeroy, as well as the Marquis de Persan and the Prince and Princess de Condé.