Inklings
"Properly speaking," wrote Warren Lewis, "the Inklings was neither a club nor a literary society, though it partook of the nature of both. There were no rules, officers, agendas, or formal elections." As was typical for university literary groups in their time and place, the Inklings were all male. 
Readings and discussions of the members' unfinished works were the principal purposes of meetings. Tolkien's "The Lord of the Rings", Lewis's "Out of the Silent Planet", and Williams's "All Hallows' Eve" were among the novels first read to the Inklings. Tolkien's fictional Notion Club (see "Sauron Defeated") was based on the Inklings. Meetings were not all serious; the Inklings amused themselves by having competitions to see who could read the notoriously bad prose of Amanda McKittrick Ros for the longest without laughing.
Christopher Tolkien
Tolkien had long been part of the critical audience for his father's fiction, first as a child listening to tales of Bilbo Baggins (which were published as "The Hobbit"), and then as a teenager and young adult offering much feedback on "The Lord of the Rings" during its 15-year gestation. He had the task of interpreting his father's sometimes self-contradictory maps of Middle-earth in order to produce the versions used in the books, and he re-drew the main map in the late 1970s to clarify the lettering and correct some errors and omissions. J. R. R. Tolkien invited Christopher to join the Inklings when he was twenty-one years old, making him the youngest member of the informal literary discussion society that included C. S. Lewis, Owen Barfield, Charles Williams, Warren Lewis, Lord David Cecil, and Nevill Coghill.