The Three Musketeers is the quintessential adventure. It has everything: action, intrigue, love, loss, daring, nobility, peasants, warfare. It is absolutely jam packed with brilliance.
I can’t think of a better example of a coming of age story either. And D’Artagnan… there is no better example for kids to emulate (not the fighting necessarily, but), he plans a little and then takes action and so do his musketeer friends, each confident in their ability to achieve a beneficial outcome.
One of the initial thoughts for The Assassin’s Cradle was: what if D’Artagnan’s interview with Cardinal Richelieu in A Message from the Cardinal had happened at the beginning of the novel? Another was: what if Cardinal Richelieu had employed D’Artagnan the way Cardinal Mazarin did later (in Twenty Years After)?
Now you know two character influences: D’Artagnan contributed to my thoughts for Idries and Cardinal Richelieu for Over-Minister Hadremoff.