Caravaggio depicted the biblical event of David defeating Goliath multiple times throughout his career. The painting that hangs in room A of the Museo Del Prado is one of the lesser known studies of this story by the italian artist, his other more famous iterations can be found in the Kunsthistorische Museum in Vienna and The Borghese Gallery in Rome, respectively.
The Prado’s David with the Head of Goliath is rather peculiar in its depiction of the event, considering the other two paintings show the boy standing firmly holding up the giant’s severed head. In this rendition, the boy is crouching down over Goliath, his face shadowy, in what is a much more small-scale, almost intimate, depiction of that moment.
One of the more overlooked works in Caravaggio’s canon, doubts still persist as to the painting’s origins and attribution to Caravaggio has not always been unanimous. You can read more about the painting and its history here.