In 1898 Aleister Crowley was introduced to the Golden Dawn by a man named George Cecil Jones. Crowley became an ardent supporter to the order's leader, MacGregor Mathers. But for a variety of reasons, Crowley lost faith and split from Mathers. He decided to form his own replacement order that was supposed to supersede the Golden Dawn. In 1907, with the help of Jones, he founded the Astrum Argentum or A∴ A∴.

The basic design for this new order was remarkable for its originality. Unlike previous orders that followed a lodge system, you were only supposed to know your immediate superior and any people you introduced to the organization. While the O.T.O. has received most of the publicity as the group that follows the teachings of Thelema, the O.T.O. was primarily designed to be a fraternal organization (until you reached the highest degrees) while the Astrum Argentum was the primary mode of transmitting Crowley's magical and mystical techniques and beliefs.

The Golden Dawn was a teaching order, preparing people to do magic in its "Inner Order." The Astrum Argentum was not a teaching order, but assumed that members were either already trained or received training from their immediate superior. After Crowley's death in 1947, several individuals claimed to continue the order, with some lineages being very clear while others or open to debate.