Among the most widely known secret societies of the classical world, the Pythagorean Brotherhood was founded by the Greek philosopher Pythagoras (c.570–c.4<95 BCE) in Crotona, a Greek colonial city in what is now southern Italy. Pythagoras had traveled from his native city of Samos to Egypt and Babylon to study mathematics, and then voyaged through the Greek islands to seek out mystery initiations, before settling in Crotona. His teachings, which centered on sacred geometry and numerology, combined mathematics and mysticism in a way that baffles many modern scholars but has close similarities to the practices of the old operative Masons.

The Pythagorean Brotherhood borrowed heavily from the ancient mystery cults but added features of its own. Candidates for membership faced a searching interview and then had to sign over all their worldly goods to the Brotherhood, to be returned if they left the society. For the first five years they had the rank of acousmatici, “listeners;” subject to a vow of silence, they were permitted to listen to lectures from behind a curtain but could ask no questions. After completing this probation they became mathematici, “mathematicians,” and worked directly with Pythagoras and his inner circle of students. Members ate a vegetarian diet and lived under many taboos. Beliefs of the society also included reincarnation and a variety of moral and philosophical maxims.

The Brotherhood drew much of its membership from Crotona’s upper classes and became deeply enmeshed in politics, supporting the aristocratic party in a series of social disputes that finally burst into violence. Around 500 BCE rioting broke out in Crotona and many members of the Brotherhood were killed; several ancient sources claim that most of the Brotherhood’s members were trapped in their headquarters, which was burnt to the ground. Pythagoras fled to Metapontum, another city not far away, where he died a few years later. Surviving members scattered throughout the Greek world. The Brotherhood may have survived in exile for a time, but there seems to be no evidence that it existed for long thereafter – a point that has not prevented a wide range of later secret societies, including Freemasonry, from claiming Pythagorean roots.


  • Sacred Geometry
  • Retrospective Recruitment


The Element Encyclopedia of Secret Societies : the ultimate a-z of ancient mysteries, lost civilizations and forgotten wisdom written by John Michael Greer – © John Michael Greer 2006