From the Wikipedia:
The Illuminati (plural of Latin illuminatus, "enlightened") is a name given to several groups, both real and fictitious. Historically the name refers to the Bavarian Illuminati, an Enlightenment-era secret society founded on May 1, 1776 to oppose superstition, prejudice, religious influence over public life, abuses of state power, and to support women's education and gender equality. The Illuminati were outlawed along with other secret societies by the Bavarian government leadership with the encouragement of the Roman Catholic Church, and permanently disbanded in 1785. In the several years following, the group was vilified by conservative and religious critics who claimed they had regrouped and were responsible for the French Revolution.