S.L. MacGregor Mathers

Samuel Liddell (or Liddel) MacGregor Mathers (8 or 11 January 1854 – 5 or 20 November 1918), born Samuel Liddell Mathers, was a British occultist. He is primarily known as one of the founders of the Hermetic Order of the Golden Dawn, a ceremonial magic order of which offshoots still exist today.