The Man in the Iron Mask
How we cite our quotes:
"Look at us, Aramis! We are three out of the four. You are deceiving me, I suspect you, and Porthos sleeps; an admirable trio of friends, don't you think so?- a beautiful relic!" (14.78)
Despite the rifts in their relationship indicated by this passage, the friends actually remain deeply loyal to each other.
"A friend's word is the truth itself. If I think of touching, even with one finger, the son of Anne of Austria, the true King of this realm of France; if I have not the firm intention of prostrating myself before his throne; if, according to my wishes, to-morrow here at Vaux will not be the most glorious day my King ever enjoyed,- may Heaven's lightning blast me where I stand!" Aramis had pronounced these words with his face turned towards the alcove of his bedroom, where d'Artagnan, seated with his back towards the alcove, could not suspect that any one was lying concealed. The earnestness of his words, the studied slowness with which he pronounced them, the solemnity of his oath, gave the Musketeer the most complete satisfaction. (14.104)
Aramis does indeed feel loyalty to Philippe.
"Yes, Monsieur, we both love him, but each in a different manner," replied La Valliere, with such an accent that the heart of the young King was powerfully affected by it. "I love him so deeply that the whole world is aware of it, so purely that the King himself does not doubt my love. He is my King and my master; I am the humblest of his servants. But he who touches his honor touches my life. Now, I repeat that they dishonor the King who advise him to arrest M. Fouquet under his own roof." (15.35)
La Valliere is probably the only person close to the King who is completely free of any personal or political agenda – she really does love the King and wants what's best for him. One could say she is the only person in King Louis's court who is truly loyal.