Aleister Crowley was born Edward Alexander Crowley in Leamington Spa in 1875, into a wealthy family of Plymouth Brethren, and spent his adult life constructing an elaborate opposition to everything that upbringing stood for. He was a mountaineer of real distinction before he was anything else, a prolific and uneven poet, and the founder of Thelema, the religious system set out in The Book of the Law of 1904.
His first substantial Paris episode is the one his own literature makes most of. Between 31 December 1913 and 12 February 1914, in Paris, Crowley and the poet Victor Neuburg carried out a sequence of ritual magic operations invoking Jupiter and Mercury — the Paris Working. The stated objects were money and inspiration. Neuburg broke with him later that year, left the order, and Crowley responded by cursing him ceremonially, which was a fairly typical resolution of a Crowley friendship.
From 1924 Paris was his base. This is the period that matters for the city, and it is less lurid and more interesting than the reputation suggests: Crowley in the twenties was moving through the same Montparnasse in which the modernists were working, known to painters, writers and photographers, a recognisable and much-discussed figure in the studios rather than a purely underground one. Tobias Churton's book-length study of these years makes the case that his Paris circle was substantially an artistic one.
It ended by order of the state. The French government issued an expulsion order in the spring of 1929, effective 17 April, and he was required to leave. The stated grounds combined his reputation as a drug user and libertine with a suspicion — never substantiated — that he had worked as a German agent. The Paris press covered the expulsion with relish; Le Populaire ran a piece on him that April under the heading of a strange figure.
He spent his last years in England, in declining health and chronic poverty, and died at Hastings in 1947. His cultural afterlife has been enormous and largely posthumous, running through popular music, film and publishing in a way that would have delighted him.