The Martyrdom of Saint Matthew (Martirio di San Matteo, 1599–1600) by Caravaggio hangs on the right side wall of the Contarelli Chapel in Saint Louis of the French church in Rome.
Caravaggio cleverly took into account that visitors have to see the painting from the side, as most are not allowed to enter the private chapel. The semi-nude assassin is seen long before visitors identify Matthew and work out the rest of the scene.