Having begun acquiring antiquities while he was in Rome, Rubens continued collecting after his return to Antwerp, and throughout his career these works continued to provide him with inspiration. The helmet, in the shape of a dolphin’s head, which is such a prominent feature of Portrait of a Man as the God Mars was itself in Rubens’s own collection. He believed it to date from classical antiquity, but it was actually a 16th-century Italian burgonet all’antica likely made by Milanese armorer Filippo Negroli. The same helmet appears in Finding of the Pagan Treasures and Judas Maccabeus’s Prayer for the Dead, painted for the Cathedral of Tournai, as well as on a soldier in the Raising of the Cross, installed in 1637 in the Abbey of Affligem, and now in the Musée Royaux des Beaux-Arts de Belgique, Brussels.

Recent research by Dr. Jeremy Wood shows that Rubens owned the helmet by 1628, yet scholarly opinion regarding the dating of Portrait of a Man as the God Mars has ranged from circa 1615 to the mid-1620s. The fluid brushwork, the light touch on the feather and fur of the man’s costume, the coloration, and the approach to light and shade are all consistent with a dating of circa 1620.

In addition to its references to antiquity, Portrait of a Man as the God Mars reflects the profound influence that Titian had on Rubens, throughout the latter’s career. Rubens made many copies of Titian’s paintings of all types – a seventeenth-century inventory made after Rubens’ death listed 33 copies after Titian made by Rubens, of which 26 were portraits – and an awareness of the Italian master’s unique and brilliant brushwork and colorism permeates his entire artistic output. Here, in addition, the sitter’s striking pose, directly engaging with the viewer, strongly resembles that of the Emperor Titus Vespasian, one of a series of portraits of the Caesars that Titian painted for the Gonzaga family in Mantua. Rubens would surely have seen Titian’s Gabinetto dei Cesari in the Palazzo Té when he himself worked for the Gonzagas in Mantua, almost a century later. Titian’s Caesars were destroyed in a fire in 1734, but their compositions are known from seventeenth-century engravings by Aegidius Sadeler II.

First documented in a sale in Amsterdam in 1827, Rubens’s Portrait of a Man as the God Mars has an illustrious provenance. After arriving in England by 1830, it entered the collection of the Rothschild family, belonging, by 1854, to Sir Anthony de Rothschild, 1st Bt., founder of the London bank and keen collector of Flemish, Dutch and French paintings. It remained with the family for some 70 years, passing to Sir Anthony’s daughter Annie, The Hon. Mrs. Eliot Constantine Yorke. Upon her death in 1926, her sister Constance, Lady Battersea, a prominent society figure and women's rights activist, organized a sale of the collection, and in 1929 the painting was acquired by legendary retail magnate and art collector Samuel H. Kress, who was, together with Andrew Mellon and Joseph E. Widener, one of the three founding benefactors whose collections formed the basis of the new National Gallery of Art in Washington D.C. Portrait of a Man as the God Mars remained, however, in the Kress family until the late 1980s, passing thereafter through other American private collections, before being acquired for the Fisch Davidson Collection in 2002.