-The underground city known as Agartha—or by a range of similar but slightly different spellings, such as Agarath or Agharti—has become a popular subject in esoteric lore. As far as we know, Saint-Yves was the first Westerner to write about Agartha, which he did in his 1886 treatise, Mission de l’Inde en Europe. This was written under the influence of several “Eastern Initiates,” including a scholar that Saint-Yves had contracted to teach him Sanskrit, who called himself Prince Hardjij Scharipf. Later, however, Saint-Yves apparently worried that he had “revealed too much,” and attempted to destroy all the copies of his book on Agartha—which would not be re-published until 1910, a year after Saint-Yves’ death. In 1908, prior to the re-publication of Saint-Yves’ Mission de l’Inde en Europe, American writer Willis George Emerson published The Smoky God, which purported to be a true account of a Norwegian sailor named Olaf Jansen, who passed through an entrance to the Hollow Earth at North Pole and lived among the inhabitants there for two years. After World War I, German occultist groups such as the Thule Society took an interest in Agartha.