Here we are presented with a young man, elegantly dressed in black, standing within a landscape beside a horse whose mane is richly adorned with blue ribbons and bows. The man wears his hair very long, as was popular during the reign of Charles II, and carries a sword at his side. Hanging on his chest is a pendant with the cross of the Order of Saint James, which also appears prominently on his cape. In his right hand he holds a rod for breaking-in horses, an equestrian reference that is completed by the image of his servant bending over to adjust his master´s spurs and the groom that restrains the horse.The fact that this painting once belonged to the noble house of Osuna, together with the pictorial style that points to Juan Carreño de Miranda and the references to the Order of Saint James, allowed scholars Allende-Salazar and Sánchez Cantón to identify the sitter as Don Gregorio de Silva y Mendoza (1649-93), who was named Knight of the Order of Saint James in the year this portrait was probably painted. In 1676, Don Gregorio inherited his father´s title as the Duke of Pastrana and, a decade later, the duchy of the Infantado from his mother. (Subsequently the houses of Osuna and Infantado joined.) The appearance of a figure with similar features in Francisco Rizi´s Auto-de-fé on the Plaza Mayor in Madrid 1683 (P1126) confirms this identification. The painting is one of the best Spanish portraits from the last third of the seventeenth century. It is also among those that best reveal the extent to which sixteenth-century Venetian and seventeenth-century Flemish painting, as well as the works of Velázquez, were points of reference for the development of the genre in Spain. Antonio Palomino referred to the first two sources of inspiration in 1724 when he wrote of Carreño´s portraits: all of them were so like his sitters´ true appearance, that it was a miracle, indeed, of the supreme refinement with which Heaven endowed him, in his blend of Titian and Van Dyck, such that, by equalling both together, he surpassed them each alone.Indeed, the similarities between this portrait and Anthony van Dyck´s Charles I, King of England, at the hunt 1635 (Musée du Louvre, Paris), in which the king is also accompanied by servant, groom and horse, have frequently been remarked upon.As in the portrait by Van Dyck or in Bartolomé Esteban Murillo´s Marquis de Legarda in hunting dress c.1660 (private collection, Madrid), Carreño´s portrait reveals a subtle play of hierarchies: in contrast to the static, erect pose of the principal sitter, his servants are crouching down or bending slightly over, carrying out some action in the service of their lord.The significance of this work is ambiguous. The sitter´s location in an exterior scene that suggests hunting or some form of rustic exercise. Yet, far from being dressed for the hunt, the duke wears sumptuous court attire, and his horse is similarly adorned. It has been speculated that the portrait commemorates his marriage to Doña María Méndez de Haro, which took place in June 1666, when the duke was 17. It is more likely, however, to be a later work, which the apparent age of the sitter -somewhat beyond 17 years- and the style of painting both suggest. In contrast to Carreño´s portraits of the Marquis and Marchioness of Santa Cruz and of the Countess of Monterrey executed in the 1660s -in which the modelling of the figures and their relationship with their surroundings is more rigid- here, the perfect integration of the figures of the duke, his servants, the horse and the surrounding scenery all come together in a coherent whole. In this regard, the portrait is closer to works such as Carreño´s Charles II wearing the robes of the Order of the Golden Fleece 1677 (Harrach collection, Austria) or Pedro Ivanowitz Potemkin, Russian Ambassador c.1681 (P645).The gentleman and his mount are dressed for public presentation, which suggests that the work reflects some ceremonial act related to the court of Charles II. It is possible that the painting commemorates one of the most important events in Don Gregorio´s biography, which took place in 1679, when he was already duke: namely, his journey to Paris to deliver to Princess Marie Louise of Orléans a portrait of her future husband, Charles II of Spain (Portús, J.: Portrait of Spain. Masterpieces from the Prado, Queensland Art Gallery-Art Exhibitions Australia, 2012, p. 104).