This interesting website has quite a bit of information on the history of the Ordo Templi Orientis or O.T.O. that was founded in it's modern context by the English archmage Aliester Crowley. I personally think it tends to accentuate the darker side of the O.T.O., but it's very informative and all off the pages are good reads.

 

 

Blessed Be,

L.B.