With its nearly square dimensions and the pronounced diagonal created by the form of the rearing horse, this picture presents a forceful image of equine power. It remained somewhat overlooked in Van Dyck scholarship until 1999, when Sir Oliver Millar upon studying a photograph of the painting, wrote that he was 'surprised' that it had been doubted as the work of Van Dyck. In 2002, he again noted that he was 'impressed' by the painting. Susan Barnes also considers this work to be by Van Dyck, positing that it was painted as an independent work of art, 'presumably to show a hoped-for patron'. She dates it to 1620-1622/3, noting that the handling of the landscape is comparable to many of Van Dyck's works from that period (facsimile of 12 May 2008).
The precedent for such monumental horse imagery is legion. The pose, with head in frothing profile, rippling muscles in the quarters, nimble legs and ample mane, may derive from prints in Stradanus' Equile Ioannis Austriaci of 1581, such as the Eques Hispanus (A. Baroni Vannucci, Jan van der Straet..., 1997, no. 692.30) or Antonio Tempesta's series Horses in different Postures or Horses from different Lands (Illustrated Bartsch, 36, 1983, pp. 160 and 202). Alternatively, Van Dyck, recollecting prints and small scale bronzes after Leonardo and by Giambologna (W. Liedtke, The Royal Horse and Rider, 1989, figs. 39-40), may have seen the present work as an opportunity to depict the horse as a subject in its own right, thus demonstrating the superiority of painting over sculpture, which had not yet found the means to cast a bronze on such a grand scale. Van Dyck's horse also invites a comparison to Virgil, evoking lines in his Georgics referring to a foal, '...His neck is high, his head clean-cut, his belly short, his back plump and his gallant chest is rich in muscles...Again should he but hear afar the clash of arms he cannot keep his place; he pricks up his ears, quivers in his lambs, and snorting rolls beneath his nostrils the gathered fire...' (H. Rushton Fairclough, Virgil with an English Translation, 1928, I, p. 161).
Comparable paintings of saddled, riderless steeds by Van Dyck exist. One such work, also a modello, was a trotting gray sold at Christie's, London, 6 April 1984, lot 82, 31 x 26 in. (80.6 x 67 cm.); it was executed in preparation for the Brignole-Sale portrait (De Poorter et al., op. cit., II, p. 32). Another larger trotting gray horse, 51½ x 39½ in. (130.8 x 100 cm.) sold at Christie's, London, 13 December 2000, lot 30, was either intended as a large-scale modello or remains an unfinished work. Originally, it depicted a rider in armor and can be related to Van Dyck's posthumous portrayal of Emperor Charles V (De Poorter et al., op. cit., nos. I.101-102 entries by S. Barnes and O. Millar).
Additional horse pictures also can be associated with Van Dyck. Presumably the 'model' for the Equestrian Portrait of Charles I in the National Gallery, London, recorded by Van der Doort in his catalogue of Charles I's collection (De Poorter et al., op. cit., nos. IV.51 and 52) also included the sitter, as does the grisaille modello for another equestrian portrait now in the collection of the Earl of Pembroke, Wilton House (De Poorter et al., op. cit., no. III.178). The two little grisaille panels (plus another, whereabouts unknown) at one stage accepted by Michael Jaffé, Oliver Millar and Julius Held as by Van Dyck and discussed by Walter Liedtke in his 1984 Metropolitan Museum catalogue, are now discounted. Perhaps in some way derived from Van Dyck, the riders can be connected with Three men on horseback, formerly in Berlin, usually thought to have been painted in Rubens' studio. The configuration of the horses in these sketches do not relate to the composition of the present picture, in which the pose is to a degree comparable with that in a little-discussed depiction of a Cossack (?) on horseback (59 x 43 in., 152 x 109 cm.) at Schleissheim, which has an old attribution to Van Dyck and is reproduced by E. Larsen, The Paintings of Anthony Van Dyck, Freren, II, 1988, no. 1046.
The pose in the present work, in reverse, appears in Van Dyck's equestrian portrait of the Prince of Arenberg at Holkham (De Poorter et al., no. III.66). Horst Vey and previous authorities believe that two drawings by Van Dyck were preparatory for the picture, one of which is now in the Metropolitan Museum, New York (C. Brown, The Drawings of Anthony Van Dyck, exhibition catalogue, 1991, no. 53). In this sheet, the horse faces right and includes a sitter who does not seem to correspond with Arenberg. Furthermore, a pentimento in the horse's rear leg accords with the one in the present painting, as does the near fore hoof, although the mane is even more agitated in the drawing. Therefore it seems possible that, given the size of the present painting, it may be the major part of an abandoned equestrian portrait, perhaps begun around 1630, in preparation for which the Metropolitan Museum drawing was also made.
Noël Desenfans, the dealer and first recorded owner of the present work, is celebrated today as the creator from 1790, with Francis Bourgeois, of the greater part of the collection of pictures in the Dulwich Picture Gallery. Richard Payne Knight, who bought it from him, was the foremost English aesthete of his generation and greatly influential, although his reputation was to be tarnished by his criticism late in his life of the Elgin Marbles. He left a magnificent bequest to the British Museum of antique coins, medals and bronzes and a large number of old master drawings. His paintings were a less widely-known section of the collection he amassed; nevertheless, apart from the present picture, he also owned major works by Rembrandt, Dou, Claude and Mantegna, among others.