June 28, 1855 – October 28, 1923
In 1880, in Munich, & 1888, in Berlin, he helped attempt to revive Adam Weishaupt’s Bavarian Order of Illuminati. While in England, he became friends with William Wynn Westcott, the Supreme Magus of the Societas Rosicruciana in Anglia and one of the founders of the Hermetic Order of the Golden Dawn.
In 1895, he began to discuss the formation of Ordo Templi Orientis with Carl Kellner.
In 1910, he made Crowley a VII° of O.T.O., and in 1912, he conferred upon him the IX° and appointed him National Grand Master General X° for the O.T.O. in the United Kingdom of Great Britain and Ireland by charter dated June 1, 1912.
Crowley’s Gnostic Mass, which Reuss translated into German and had recited at his Anational Congress at Monte Verità, is an explicitly Thelemic ritual.