Israel Regardie

Israel Regardie, born Israel Regudy (17 November 1907 – 10 March 1985) was an English occultist writer, notable for publishing books about the Hermetic Order of the Golden Dawn.

Biography
For many years, Regardie was a member of several Hermetic Orders, such as the Golden Dawn and its successor group,. He eventually grew disillusioned with the direction they had taken and wanted to distance himself from them.

In spite of this, Regardie's beliefs remained strong and were a guiding force in his life. He became afraid that the internal strife within many of the Hermetic Orders would destroy the teachings that they had espoused. In order to preserve these teachings and secure their survival, Regardie acquired most of Stella Matuntina's documents after the group had disbanded.

Having compiled the documents, Regardie released a book titled  in 1934. The book revealed many of the most secret inner workings of the Hermetic Tradition to the public. Although many of Regardie's peers branded him an oath breaker, the book inspired a completely new branch of Western Hermeticism and ensured the continued survival of modern occult organizations.

Reference

 * Assassin's Creed: Initiates - Modern Times: "Tattletale"