Paul Sédir, pseudonym of Yvon Le Loup (1871-1926), was a pivotal figure of the fin-de-siècle French occult revival. He was a professor at the École hermétique and Faculté des sciences hermétiques in Paris under the directorship of Papus, his first spiritual mentor. He practiced magic with the alchemist Albert Poisson and was initiated into almost all of the secret societies that occult Paris had to offer. Under the name Tau Paul, he was consecrated bishop of Concorezzo in the Église gnostique de France. He wrote widely on traditions of magic, mysticism, and esotericism, publishing over twenty books in French.