Basic OTO International Headquarters website that provides the links to the different Grand Lodges and national OTO websites.

The US Grand Lodge website is the most comprehensive of the official OTO sites. You find pretty much everything there: membership information, articles on the history and general introductions on Thelema, the thelemic calendar and more. Make sure you pay the libary a visit, where you can find a wealth of documents and the archive of the newsletter Agapé.

The UK Grand Lodge under Hyperion X° was eastablished on the 1st of May 2005 e.v. at a celebratory Gnostic Mass at Conway Hall in Red Lion Square, London. 93 years to the month after the previous X° for the U.K., Aleister Crowley, was elevated to that office.

Unoffical archive of essays and materials relating to the Ecclesia Gnostica Catholica (E.G.C.) and the Gnostic Mass. This site is intended to serve as a resource for those interested in the E.G.C., the Gnostic Mass, and in Thelema, with writings by Sabazius, Dionysos Thriambos nd others. It's hosted on hermetic.com.

Peter R. König's popular and controversial research on the O.T.O. and other oranisations such as Fraternitas Saturni is mainly concerning the history and legitimacy of the OTO, but he is generally known to collect as much information as possible and probably has one of the best archives in the world by now. Having said that, when it comes to interpretation of the data, his work (in my humble opinion) is to be taken with many, many grains of salt. Speculations and conclusions are fuelled by a negative attitude towards the main protégés and particularly towards the Caliphate OTO. But this is without any doubt still a very good source of information that you won't find anywhere else and I believe anybody interested or involved in the OTO is actually well advised to also at least listen to opinions of critics to then make up their own mind rather than blindly believing anything. That, and imho only that, is the thelemic way as opposed to old aeonic faith.

Rodney put together a timeline containing quotations of some of the key documents from the 1940s until 1969 when McMurtry reactivated the order. While this is admittedly written by an OTO member and cannot explain all events in full detail, this text provides a really nice summary and covers most arguments that you would come across.

Homepage of Sabazius X°, who became the first X° under Hymenaeus Beta XII° on the 30th of March 1996 e.v. You can find some his essays, a fewe E.G.C. rituals, his weblog and more.

Articles written by Marco Visconti on Medium, which are his attempt at "teaching the essence of Thelema to a wider public outside the bonds of oaths and secrets."

Basically an article from am OTO critic, in which he basically claims that the OTO is clandestine (i.e. fake) masonry. I don't share his point of view, not least because OTO doesn't claim to be true Masonry in our days and the article is relatively old and further research has corrected some of its claims, but it's still and interesting read.