The Pentacle Club is one of the world's oldest magic societies founded in 1919.
The Pentacle Club was founded on May 14, 1919, by Professor W. W. Rouse Ball (President), J. H. Johnson, C. R. Cosens, F. J. W. Roughton and W. I. Grantham (Secretary and Treasurer). The Club consisted of members of Cambridge University who were interested in magic.
The Pentacle Club was the successor to "The Mystics" which was founded in 1909 and lasted to the outbreak of war in 1914. There is evidence to show that another club had existed before the First World War called "The Cambridge University Magical Society" or the "Cambridge University Society of Magicians".
Roger Crosthwaite was a member in the early sixties.