In the world of The Three Musketeers, gentlemen are typically very proud and do not take insults lightly. A casual misunderstanding frequently results in a duel; in order to preserve their pride men will fight to the death. Wounded pride is not always so easily resolved, however, and the desire for vengeance is one of the driving engines of the novel.
Athos is by far the proudest of the four friends.
The Cardinal’s pride is responsible for his attack on La Rochelle.