The Illuminati (plural of Latin illuminatus, "enlightened") is a name given to several groups, both real (historical) and fictitious. Historically the name refers to the Bavarian Illuminati, an Enlightenment-era secret society founded on May 1, 1776.
Since the publication of Robert Shea and Robert Anton Wilson's postmodern science fiction work The Illuminatus! Trilogy (1975-7) the name has been used to refer to a purported conspiratorial organization that masterminds events and controls world affairs through governments and corporations to establish a New World Order. In this context the Illuminati are usually represented as a modern version or continuation of the Bavarian Illuminati.