Leighton uses a Greek myth (concerning the daughter of Debutades) as the basis for this scene. Here, the woman traces the departing knight's shadow against the wall. There are several versions including one in Cardiff and one in Alabama.
One of a series of similar depictions at the Martim Moniz Metro station in Lisbon, Portugal. This one shows the 12th-century crusader, Arnout IV, Count of Aarschot.
Another scene from Tasso's Jerusalem Delivered, this time showing two Christian knights confronting a dragon in an attempt to rescue Rinaldo from a sorceress