The Musee du Louvre is collaborating with the Museo del Prado to present the work of the artist Ingres, who was a portrait painter. He is claimed to have both admired this type of art works, and both rejected it as true art form, and viewed it as more of a commercial endeavor. He did desire to be recognized as a history painter, and for this reason he painted portraits.
I personally think that capturing the essence of who a person is in a painting is the most fascinating of all the art undertakings. He is of course remembered as a genius of the portrait, and I particularly am interested in see his portraits of Napoleon I on His Throne and Joan of Ark.