The two kings and two queens face off (La Reine Margot, I, 3 for L'Illustration, Feb. 20, 1847) - Valentin

The review in L'Illustration is incendiary. Here's how the journalist introduces the final tableau of Act I, chosen for the engraving:

"At the same time, and at another end of the Louvre, King Charles IX, tête-à-tête with Henri de Navarre, posed this alternative to him: death or mass, and to escape the itch to unload his arquebus in the chest of his brother the Bearnais, he killed a parpaillot from the top of that window of the Louvre reported from time immemorial as having served as the theater for this forfeit. At the sound of the explosion, the Queen Mother runs over, while the crime is being committed; Marguerite also runs over to warn him, if there's still time. This is the most animated tableau in this languid, drawn-out act; the two kings, the two queens, agitated by contrary, bloody passions, form a spectacle of dramatic energy and warm coloring that the drawing had to try to reproduce." (L'Illustration, February 20, 1847, p. 403)

To the right, then, Charles IX and Catherine de Médicis his mother. On the left, the future Henri IV and Queen Margot.