 Kains Jackson was a member of the Order of Chaeronea, a secret society for homosexuals founded in 1897 by George Ives, which was named after the location of the battle where the Sacred Band of Thebes was finally annihilated in 338 BC.Other members included Samuel Elsworth Cottam, Montague Summers, and John Gambril Nicholson.Jackson discovered the poetry of Edward Cracroft Lefroy.