The founder of the infamous Bavarian Illuminati.
Weishaupt, as a student from a Jesuit background, had earlier formed a student society that sought to recreate the Ancient Mysteries and combine them with a socialist worldview. He was particularly interested in Pythagoreanism, Platonism and the Mithraic and Eleusinian Mysteries, elements of which he also seems to have later introduced into the Illuminati.
Later he became enamoured of atheistic Enlightenment Philosophy (particularly Voltaire, John Locke, Rousseau, Holbach and Helvetius) and sought to reconcile this with his earlier beliefs. He found a bridge between the two in his interpretation of thePantheism of Baruch Spinoza.
Another important influence on him was an alleged meeting with the mysterious Kolmer. This eccentric figure was said to be making his way across Europe, trying to convince people to help him in his idiosyncratic mystico-political project. What this was is unknown, but it seems to have included a type of Gnostic anarchism and a form of radical Islam (apparently Kolmer’s interpretation of Ismailism and the ‘secrets’ the Assassins. Kolmer was last heard of associating with the French Illumines (whom he had close contact with both before and after his association with Weishaupt). Weishaupt would introduce elements of these ideas into the Illuminati.
On becoming a university professor Weishaupt was initiated into Freemasonry but was unimpressed by his fellow Masons.
Weishaupt distilled all of the above into his secret society which he formed in 1776 with four friends. Weishaupt taking the codename Spartacus. By 1782 it had grown to an organisation of several hundred members spread throughout Europe.
Despite his arguably good intentions Weishaupt seems to have demonstrated increasingly megalomaniac tendencies, as well as paranoid beliefs that he was under attack from the Jesuits and Rose Croix Freemasons.
In 1785 the Bavarian Illuminati was surpressed by the state and broken up, and Weishaupt was sacked. He spent the rest of his life in semi-retirement as a private tutor.