Joséphin Péladan was a colorful figure in late 19th and early 20th century France. Here's a quick rundown:
French Novelist and Rosicrucian: He was a prolific writer, but also interested in the mystical traditions of Rosicrucianism. He even founded his own Rosicrucian order focused on aesthetics and Catholic ideals. Wikipedia
Salon Organizer: Péladan wasn't just a writer, he was an organizer. He founded the Salon de la Rose + Croix which showcased art that aligned with his aesthetic and mystical sensibilities. https://www.goodreads.com/author/list/803545.Jos_phin_P_ladan
Controversial Figure: Despite his interesting ideas, Péladan wasn't always taken seriously. His idiosyncrasies and mystical leanings led to him being somewhat of a footnote in art and esoteric circles. https://peladan.net/symbolist-art/who-was-josephin-peladan-3/