Which Oxford academic group did J.R.R. Tolkien regularly attend with C.S. Lewis?

J.R.R. Tolkien regularly attended The Inklings with C.S. Lewis.

The Inklings was an informal literary discussion group associated with the University of Oxford. Its members and guests met mainly at Lewis’s college rooms and at The Eagle and Child pub, which was known to them as the Bird and Baby. The group was active chiefly during the 1930s and 1940s.

Tolkien and Lewis read drafts of their work aloud, discussed literature, and encouraged one another’s writing. Tolkien’s participation overlapped with the development of The Hobbit and The Lord of the Rings, while Lewis was working on books that later became The Chronicles of Narnia and other works.

The Inklings was not a formal university society with a fixed membership list or constitution. That informality is why descriptions of its members can vary. Charles Williams, Owen Barfield, and Warren Lewis were also important figures in the group. The name should not be confused with the Bloomsbury Group, a different British literary and artistic circle centered largely in London.