In spite of its title, this painting is not a portrait, but the depiction of a young man in fancy dress. Studies of figures wearing exotic costumes were popular in seventeenth-century Holland, and were frequently produced by Rembrandt and his circle. The dress and dramatic lighting here suggest that this man is a figure from history, although there are no attributes to point to a specific character. It has been suggested that Lievens himself, or possibly Rembrandt, modelled for this painting, but it was certainly not intended to be a portrait. This painting is considered to be one of Lievens’s greatest works, and may have been inspired by the friendly rivalry between the two artists, which ended when Rembrandt moved to Amsterdam.