This is one of the few known images of the brother of King Felipe IV and Velázquez painted it some years after the infante's death. He wears a black suit with grey highlights and a short cape, and the superb gold chain and fleece are the only adornments. Little is know of don Carlos, who spent most of his life in the shadow of his brother, although he is known to have enjoyed painting and poetry.

Velázquez manages to reflect the infante's indolent character, a result of his situation at court. The figure's placement over a neutral background and the way it is shaped with gradations of light and with the shadow it projects on the ground, make this one of the artist's most successful portraits. Especially worthy of note is the beauty of the right hand, which loosely holds a glove, while the left holds a felt hat very naturally.

This painting is documented from its origin in the Alcázar Palace in Madrid, and later in the new Royal Palace, entering the Prado Museum in 1827 from the Academy of San Fernando.