The picture probably shows the King of France kneeling with a bishop to ask forgiveness of Saint Giles. A member of the Royal Hunt had shot at Saint Giles' companion hind (deer), but injured the saint, who was protecting her. The tower in the background is probably that of Pontoise.
This and 'The Mass of Saint Giles' are part of an altarpiece which included 'Episodes from the Life of a Bishop Saint' and the 'Baptism of Clovis' (both in Washington). The costume suggests the dating of 1500.