Whistler's Copy after 'La Réunion des cavaliers', of the School of Velázquez dates from his student days in Paris, and was probably painted in October 1858 or early in the following year.

1856: On 17 June 1856, Whistler, sponsored by Marc-Charles-Gabriel Gleyre (1806-1874), obtained permission to enter the Musées Impériaux, Paris, 'pour les jours d'étude' (on study days). 1

1858: According to the Pennells, Ignace-Henri-Jean-Théodore Fantin-Latour (1836-1904) remembered Whistler copying a 'group of cavaliers' after a painting by Diego Rodriguez de Silva y Velázquez (1599-1660) (presumably the picture that entered the Louvre in 1851). 2 Fantin-Latour is said to have met Whistler at the Louvre on 7 October 1858, which suggests that Whistler's copy of the 'group of cavaliers' dates from late 1858 or early 1859.

As in the cases of several other copies, including Copy after a Picture of an Inundation [YMSM 016], Copy after Odier's 'Episode de la retraite de Moscou' [YMSM 017], Copy after a Group in Couture's 'Romains de la décadence' [YMSM 018] and Copy after Boucher's 'Diane au bain' [YMSM 020], there is no record in the Archives du Louvre of Whistler being registered with permission to copy La Réunion des cavaliers.