One early and influential source on these entities is Karl von Eckartshausen, whose The Cloud upon the Sanctuary, published in 1795, explained in some detail their character and motivations.
Several 19th and 20th century occultists claimed to belong to or to have contacted these Secret Chiefs and made these communications known to others: Aleister Crowley (who used the term to refer to members of the upper three grades of his order, A∴A∴), Dion Fortune (who called them the "esoteric order"), and Max Heindel (who called them the "Elder Brothers").
[citation needed] The Hermetic Order of the Golden Dawn was founded by persons claiming to be in communication with the Secret Chiefs.
One of these Secret Chiefs (or a person in contact with them) was supposedly the (probably fictional) Anna Sprengel, whose name and address were allegedly decoded from the Cipher Manuscripts by William Wynn Westcott.
In 1892, S. MacGregor Mathers (another founder) claimed that he had contacted these Secret Chiefs independently of Sprengel, and that this confirmed his position as head of the Golden Dawn.