On the matter of Atlantis - Saint-Yves believed the Atlantis was an advanced superior civilization. According to Saint-Yves the Sphinx was built by the Atlanteans, many thousands of years before the rise of Egypt. Saint-Yves placed the downfall of Atlantis at around 12,000 B.C.
Another source of inspiration for Saint-Yves were the medieval Knights Templar, which he regarded as the ultimate Synarchists in history. After all, the Knights Templar exerted control over the political, financial, and religious life of medieval Europe. These three pillars of medieval society corresponded with Saint-Yves' model of Synarchy.
Saint-Yves was influenced by the many neo-Templar societies that were flourishing in his day. He incorporated many of their ideas, in particular from a Masonic-Templar order called "the Rite of Strict Observance", which was founded around 1740-1750 by German Karl von Hund. Saint Yves borrowed the concept of "Unknown Superiors" from Von Hund , however he expanded the concept into "spiritually advanced beings that lived in a remote part of Tibet", aka "Agartha".
Saint-Yves d'Alveydre had many followers within the Martinist Order. Saint Yves' ideas have become part of subsequent occult "beliefs", mainly because they were also taken up and popularized by one of the most influential occultists of modern times, Helena Blavatsky (1831-1891), founder of the "Theosophic Society".
Blavatsky's work had an enormous impact on various esoteric organizations, mainly those which were established in the beginning of the 20th century. For instance, many of Blavatsky's concepts were incorporated into the teachings of Alice Baily (1880-1949), and it is generally known that Baily's teachings have had a huge influence over the beliefs of the New Age movement of today.
Then there is Rudolf Steiner (1861-1925) who used Synarchy as a major influence when he developed his own ideas for his own organization, the "Antroposofische Gesellschaft" (established in 1913, Steiner developed a philosophy which is known as "Antrosophy").
Steiner was a former member (and high dignitary) of the "Theosophic Society" in Germany. One of Steiner's former disciples, Max Heindel (1865-1919), founded the "Rosicrucian Fellowship" in 1908. All these organizations, and I just named a few of them, propagated several of the ideas which were "introduced" by Saint-Yves in a way. The principle of "Masters" is a well known concept within many of the esoteric organizations. The original concept did not descend from Saint-Yves, but he was probably one of the first in the West who introduced the idea of the hidden realms of these Masters, Adepts and Initiates which were situated in the East.
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