Sir Francis Dashwood, by Hogarth. Sir Francis had a gentleman's club, called the Monks of Medmenham which met in the ruins of Medmenham Abbey. Members included the most influential men of the age, among them Prime Minister Bute, and Frederick, Prince of Wales. They were reputed to indulge in sex orgies and black magic. The monks also met in catacombs said to be haunted by a nun named Agnes whose meetings with her lover, the priest at St. Lawrence church, were said to continue after their deaths.
Legend has it that Dashwood disguised himself as Charles XII of Sweden (in fact, already dead) in order to seduce the Russian Tsarina Anna Ivanovna when he visited St. Petersburg in 1733.
John Montagu, Lord Sandwich (the face in the halo) and George Selwyn, (a close friend of Horace Walpole who visited in 1763) were among the inner circle of twelve. One of the female members, Lady Betty Germaine, became a particular friend of Walpole's; through her Walpole acquired one of Dr. Dee's celebrated scrying stones, the Angelic Stone, now in the British Museum. Mary Wortley Montagu, Lord Sandwich's grandmother and a member of the earlier Hellfire Club, was also said to have been a member.
Satirized in the novel Chrysal, or the Story of a Guinea by Charles Johnstone, and referenced in Charles Churchill's The Candidate, these Medmenhamites were a probable influence on Matthew Lewis's The Monk
Benjamin Franklin joined the group on occasion and collaborated with Sir Francis to revise the Book of Common Prayer or Franklin Prayer Book still in use in America. Franklin was also associated with the radical Lunar Society which included Erasmus Darwin, Richard Edgeworth (Maria Edgeworth's father), and William Godwin's friend, Joseph Priestley.
Dashwood and Montagu also founded the Dilettanti society which promoted Italian art and made the works of Salvator Rosa, an important influence on Ann Radcliffe, popular in Britain. Another, the Divan club, was restricted to those who had travelled to Turkey. Mary Wortley Montagu was a member of this group as well.
Percy Bysshe Shelley once lived near Medmenham Abbey and did some of his writing here.