Tolkien's fiction sharply divides opinion. Readers of extreme learning and sophistication, and of none, admire The Lord of the Rings and The Hobbit. An apparently insatiable demand for more led to the publication, during and after Tolkien's lifetime, of an enormous volume of material supplementary to these books. At the same time, many people, from exactly the same sorts of backgrounds, found them unreadable.

Tolkien was not originally writing for a mass audience. Yet his work achieved what might be called cult status for many, despite their differing sharply from him in education and in cultural and political stances. For many who were young in the 1960s, his books seemed to offer a myth with which to interpret reality. Widely translated, they won the accolade of parody; his characters were taken into pop art and their names adopted by rock bands; his work spawned many imitators, and is an important progenitor of modern fantasy fiction. ‘Tolkien’ became a successful marketing operation – one which Tolkien himself regarded with some ambivalence. Furthermore, his work still generates much critical and scholarly debate, from the standpoints of numerous critical persuasions; and while ‘Frodo and the Hobbits’ rocked away into oblivion, Frodo and his world were discussed at several international scholarly conferences, their Proceedings filling large volumes.

The books sustaining this unusual cultural phenomenon present problems. Classifying them as ‘fantasy’, which is common practice, begs many questions, though it is difficult to know what other term to use. For, since Tolkien wrote, and partly because of him, ‘fantasy’ has acquired a range of meanings: to some, it means no more than lurid covers enclosing more lurid stories, or video games; while others, like Todorov, Hunter, Irwin, Jackson, or Swinfen, have explored it theoretically as an important genre with its own rhetoric. Tom Shippey, one of the most perceptive of Tolkien's critics, points out that fantasy's roots lie in the beginning of European literature. In its broadest definition it would include everything from the Odyssey to Beowulf to Cinderella to Terry Pratchett: it ‘makes deliberate use of something known to be impossible’, or, as C. S. Lewis put it in An Experiment in Criticism (1961), ’impossibles and preternaturals’.