This portrait of an unknown Spanish nobleman was previously identified as Don Luis Méndez de Haro y Guzmán; 6th Marquis of Carpio (1598-1661); however, the coat of arms in the lower right corner of the picture are not those of Don Luis. The inclusion of the reverse crescent on a red ground in the first and fourth quarter of the heraldic shield can be identified with the De Luna branch of the house of Aragon. The tree flanked by two birds, possibly an eagle and a crow in the second and third quarters has yet to be identified.

 he wheellock pistol upon which the sitter rests his right hand and the inclusion of a group of soldiers in the background suggests that he may be a military commander. The red sash, visible beneath the black open surcoat was traditionally worn to denote loyalty to the Spanish Habsburg dynasty.    

A drawing attributed to the little know Spanish artist Lorenzo Álvarez depicting a group of men similar to that seen in the background of this portrait was sold at Sotheby's on the 29 July 1926 (Lot 38); its present whereabouts are unknown.