Success did not come immediately, and his first exhibition was a failure. In 1761, he became a supernumerary member of the Académie royale de peinture et de sculpture and was promoted to full member in 1763. As a result of favourable criticism from Denis Diderot, he began to receive commissions from the aristocracy. Diderot would later express negative opinions about Casanova's work, but his reputation was already made. His fame soon spread eastward and he received commissions from Catherine the Great for the Hermitage, beginning in 1768. Two years later, he produced his four famous "disaster paintings", which were purchased by Jean-Benjamin de la Borde on behalf of King Louis XV. In 1771, he exhibited two large canvases depicting scenes from the Thirty Years' War (The Battle of Freiburg and the Battle of Lens) and once again won Diderot's approval.