Cardinal Mazarin - https://en.wikipedia.org/wiki/Cardinal_Mazarin

Athos - https://en.wikipedia.org/wiki/Armand_d%27Athos

Porthos - https://en.wikipedia.org/wiki/Isaac_de_Porthau

Aramis - https://en.wikipedia.org/wiki/Henri_d%27Aramitz

Comte de Troisville (D'artagnan's mentor) - https://en.wikipedia.org/wiki/Comte_de_Troisville

All highly fictionalized and I have had trouble finding information on the real counterparts (aside from the Cardinal). I started learning about that period of history after listening to the D'Artagnan Romances in audiobook form.

The other interesting thing is Gatien de Courtilz de Sanras wrote semi-fictional accounts of D'Artagnan, published 27 years after D'artagnan's death and 144 years before Dumas' The Three Musketeers ( https://en.wikipedia.org/wiki/Gatien_de_Courtilz_de_Sandras ).

And he was more than a big deal. One of the most powerful people in Europe at the time.

A hero and a heroic death in a pointless war.