Freemasonry, one of the oldest and most well-known secret societies, was first established in medieval Europe as a guild for stonemasons and later expanded to admit non-tradesmen.
Despite popular conspiracy theories, the Illuminati was actually a short-lived Enlightenment society in the late 18th century Germany aimed at opposing religious influence and abuses of state power.
Founded in 1954, the Bilderberg Group holds annual private conferences with approximately 150 invite-only attendees. Its highly secretive nature has made it a frequent subject of conspiracy theories.
Originally a medieval Christian military order, the Knights Templar have been mythicized as protectors of the Holy Grail and have inspired numerous other secret societies.
Skull and Bones is a secret society at Yale University known for its powerful alumni, including several U.S. Presidents. Its rituals and membership remain confidential generating many rumors.
Rosicrucians refer to a spiritual and cultural movement that arose in Europe in the early 17th century. It mixes Christian mysticism with Hermetic philosophy and reportedly has secret rites and ceremonies.