It is known that his main interests were magic and the theory of war, his first book being a translation of a French military manual, Practical Instruction in Infantry Campaigning Exercise (1884).

Working hard both for and in the SRIA he was awarded an honorary 8th Degree in 1886, and in the same year he lectured on the Kabbalah to the Theosophical Society.

[citation needed] In 1891, Mathers assumed leadership of the Hermetic Order of the Golden Dawn upon the death of William Robert Woodman.

[4] After his expulsion from the Golden Dawn in April 1900, Mathers formed a group in Paris in 1903 called Alpha et Omega (its headquarters, the Ahathoor Temple).

They have had considerable influence on the development of occult and esoteric thought since their publication, as has his consolidation of the Enochian magical system of John Dee and Edward Kelley.

One of his most notable enemies was one-time friend and pupil Aleister Crowley, who portrayed Mathers as a villain named SRMD in his 1917 novel Moonchild.

I wrote to him offering to place myself and my fortune unreservedly at his disposal; if that meant giving up the Abra-Melin Operation for the present, all right.

Aleister Crowley wrote in his Confessions of the decline of the Hermetic Order of the Golden Dawn, as well as that of MacGregor Mathers.