History of the Palace of Versailles czar Peter the Great stayed at the Grand Trianon. His time at Versailles was used to observe and study the palace and gardens, which he later used as a source of inspiration when he built Peterhof on the Bay of Finland, west of Saint Petersburg. During the reign of Louis XV, Versailles underwent transformation but not on the scale that had been seen during his predecessor's reign. When Louis XV and the court returned to Versailles in 1722, the first project was the completion of the Salon d'Hercule, which had been begun during the last years of Louis XIV's reign
History of the Palace of Versailles but was never finished due to the king's death. Significant among Louis XV's contributions to Versailles were the "petit appartement du roi"; the "appartements de Mesdames", the "appartement du dauphin", the "appartement de la dauphine" on the ground floor; and the two private apartments of Louis XV – "petit appartement du roi au deuxième étage" (later transformed into the "appartement de Madame du Barry") and the "petit appartement du roi au troisième étage" – on the second and third floors of the palace. The crowning achievements of Louis XV's reign were the construction of the Opéra and the Petit Trianon.