Who is Gabriele D'Annunzio from The Art of Seduction and what is their importance?

Gabriele D'Annunzio was one of the men famous for being very seductive even though he was not remotely handsome. Perhaps it was his ability to turn the tables because of situations granted him due to his lack of attractiveness. His contribution to the art of seduction, and his ability to show how powerful having the support of the high society ladies really was, are the focus of his place in The Art of Seduction.