Born 28 September 1750 in Picquigny, Picardy in France, Thibault was trained at the Royal Academy of Architecture in Paris. At the time, the Academy under Ange-Jacques Gabriel, provided the best architectural training available. Gabriel was an architect in the classical tradition, and had an important formative influence on Thibault's style. After qualifying at the Academy, details of the next few years of Thibault's life are unknown. It is known, however, that he studied military engineering in Paris under the sponsorship of Colonel Charles Daniel de Meuron.