The story is told in Livy's History of Rome (though Le Brun's source may be the shorter account given by Valerius Maximus): Horatius Cocles alone defends the Sublician bridge against the Etruscans while it is demolished behind him; above hovers an allegorical figure of Rome and in the foreground is a River God representing the Tiber. "Horatius Cocles defending the Bridge" was painted under Poussin's influence early during Le Brun's stay in Rome.