The oldest of the Three Musketeers
in Alexander Dumas
's famous book, Athos is also the highest ranking and the most clinically depressed
He has a tragic history involving a beautiful young woman whom he marries and who he later discovers to be a convicted thief. He hangs her with his own hands. Feeling that his ancient family name is forever besmirched by his unfortunate marriage, he resolves to live incognito as a lowly musketeer.
Even though I knew the book by heart before I ever saw the movie, Athos will still forever bear Oliver Reed's face in my mind. His portrayal in the '70's movie was breathtaking.