20. Hermetic Order of the Golden Dawn
Also known as the Golden Dawn this was a “magical order” active in Great Britain during the late 19th and early 20th centuries, which practiced theurgy and spiritual development. It has been one of the largest single influences on 20th-century Western occultism.
Foresters Friendly Society is a British friendly society which was formed in 1834 as the Ancient Order of Foresters. Although not as secret or mysterious as some of the others on this list its nearly 70,000 strong membership deserves some mention. As far as purpose is concerned, as with most friendly societies it primarily seeks to provide insurance policies to its members.