Goya's startling painting stands as one of the most memorable images of man's inhumanity to man. Napoleon's armies occupied Spain, but on the second of May 1808 the citizens of Madrid rose up against the French. The following day the French army took a terrible revenge by executing hundreds of the rebels and many more who were innocent bystanders. Goya was not able to record the events until half a decade later when King Ferdinand VII was restored to the Spanish throne. The painting transcends its specific historical setting and displays two principal features of Goya's art: his ability to produce images that are strikingly direct, and his questioning but ultimately detached morality.

Esthetically and historically, Goya's painting is the reverse of David's The Oath of the Horatii . The latter sets up a familiar image of the hero, willing to die for a cause. Goya gives us the anti-hero; not the warrior, but the victim whose death becomes, almost by chance, a rallying point for those struggling against oppression. Goya's style also contrasts with David's, with few clear outlines, and loose succulent paint full of ambiguities and subtleties. Note the pose of Goya's soldiers echoes in reverse, that of David's Horatii. The pose of the central victim, his arms thrown wide, is a heart rending cry for humanity against tyranny and barbarity, which is all the more poignant for its futility.