Question

why did D'Artagnan apologise​

Answer 1

Answer:

Before beginning his duel with Athos, d'Artagnan apologizes to Porthos and Aramis. They frown, thinking that he is backing down, but he explains that he is only apologizing in advance in case Athos kills him and thus prevents him from meeting his other two obligations. This impresses them, and they accept his apology.

Explanation:

Answer 2

Answer:

D'Artagnan apologises in case he was unable to keep his word to all these of them, especially Porthos and Aramis. As Athos had the right to kill him first, then Porthos, then Aramis.