Dear Peter,
There is a wonderful book with a whole chapter devoted to Baudelaire, Valéry, Poe -- it was written in Italian, but it's one of the best essays on Romanticism ever published.
The title is -- "Flesh, Death and Devil in the Romantic Literature" by Mario Praz.
P.S. Never pronounce the author's name out loud. He's dead now, but he has a strange reputation among English professors in Italy -- like, the last one who did mention his name loud....*died all of a sudden*!  <smile>...but it did happen actually.