Face to face with two identical kings, d'Artagnan is ordered to choose. He arrests Philippe, then tells him the soldier's whole political theory: “je ne suis qu’un soldat, et mes serments sont à celui qui sort de cette chambre.” Legitimacy isn't blood or right — it's exit. Fouquet adds the corollary — Philippe is “roi bien autant que l’autre” — and d'Artagnan finishes it: “Plus! répliqua d’Artagnan. Il ne lui manque que moi et vous.” A king is whoever the swords stand behind.

— In our words · Source: The Man in the Iron Mask (Alexandre Dumas)