This painting was an official commission by the Ministère d'Etat in commemoration of the reception of the ambassadors of the king of Siam, Rama IV, by Napoleon III and the Empress Eugénie in the great Salle de Bal in the Château de Fontainebleau, 27 June, 1861. The event not only marked the re-establishment of diplomatic relations (broken off since the 17th century) but also the signature of the treaty between France and Siam, 15 August, 1856, which ensured peace between the two countries, religious freedom for missionaries, and commercial dealings. The embassy was received with great pomp at a ceremony which mirrored the famous 1684 Siamese embassy to Louis XIV.
Gérôme took three years to finish this large painting, which shows the unusual procession of the bowing ambassadors, a long horizontal movement contrasting strongly with the verticality of the members of the Imperial court. The curious ceremonial is an asiatic tradition: even though they enter in a line on all fours, the Siamese king's envoys are not expressing submission to but rather respect for the sovereign. The exoticism of the scene is reinforced by the sumptuous costumes, the coloured silk robes, the pointed hats decorated with burnished gold, the lavish gifts, the crown, palanquins, stepped parasols, and replicas of objects belonging to the King of Siam and subsequently held in the Empress Eugénie's Chinese Museum. On the dais transformed into a throne, Napoleon III, flanked by Eugénie and the young Prince impérial, receives a chalice containing a letter from Rama IV.
Taking his inspiration directly from David's 'Sacre de Napoléon Ier', Gérôme here painted a remarkable gallery of portraits, either taken from nature or from photographs by Nadar. 80 personalities can be identified, including the Comte Walewski, the Duc de Bassano, the Duc de Cambacérès and Mérimée. The distant vantage point, required so as to be able to get the whole of scene in the picture, makes it possible to reveal all the Renaissance splendour of the Salle de Bal with its frescoes by Nicolo dell'Abate after Primaticcio. The exactitude of the rendering gives a strong sense of reality. Indeed Gérôme fixed with almost photographic accuracy this strange encounter of East and West.