Porthos was portrayed as loud, vein and self important, but also as a courageous friend throughout the novel. His mistress is Madame Coquenard the wife of a wealthy attorney. Porthos never completely trusts her and seems to use her.
Now that I have completed the novel, it is easy to label Lady De Winter as one of the most important characters in the story line; she is described as mysterious, beautiful and dangerous 2/3 into the novel. The end of the novel proves all three descriptions correct. The reader sees her as an ultimately evil cardinalist agent. At one point D"Artagnan becomes obsessed or "in love" with her, but eventually she and the musketeers become enemies. This lady has a secret and will kill anyone who finds it out. Also her left shoulder is marked with the Fleur-de-Lis, a mark put on the worst criminals.
Another key character is Madame Bonacieux. She is the wife of Monsieur Bonacieux and is lady-in-waiting for the Queen whom she is loyal to. She is the reason D"Artagnan gets involved in the Queens" secret affairs (which is a major focus in the novel). Her husband Monsieur Bonacieux is D"Artagnan's landlord and first comes to D"Artagnan for help when his wife had been kidnapped, but after a meeting with the cardinal, he turns on his wife and becomes a cardinalist agent, thus making him the enemy.
The enemy himself is Cardinal Richelieu, he is the kings most influential advisor, and also the most powerful and important man in France. He tries to manipulate D"Artagnan and many others. The King of France (Louis X111) is not much of a ruler. Those around him, mostly Cardinal Richelieu, manipulate him. He is easily controlled and has a raging temper. He is also clueless about what is going on around him and shows no emotion. Both the King and the cardinal do not trust or particularly like the Queen Anne. .
Queen Anne is the Queen of France, and is also Spanish. Her loyalties are divided between her Spanish heritage, her position as Queen of France, and her love for George Villiers, the duke of Buckingham.