The Illuminati (the “enlightened ones”) was a late 18th century German political secret society. Adam Weishaupt, a Bavarian philosopher and lawyer, started the secret society on the 1st of May 1776 at the University of Ingolstadt . In 1785 it was outlawed in Bavaria.
Later, other groups formed using the same name. There is no evidence that these present-day groups have any significant power or influence. They promote themselves using the Bavarian Illuminati to attract membership.