<p>J.R.R. Tolkien&rsquo;s literary cosmos may not be the most elaborate of the imaginary worlds in existence, it is certainly the most influential. The posthumous editorial work of Tolkien&rsquo;s son Christopher has also shown that Arda remains unrivalled in its consistency and complexity. Additionally, the re-publication of Tolkien&rsquo;s Andrew Lang lecture &lsquo;On Fairy-stories&rsquo; (originally delivered 1939) and its interpretation within the discourse of literary fantasy has further strengthened his position as one of the foremost proponents of literary world-building or, as he himself preferred to call it, (literary) subcreation.</p><p>The contributions to this volume by Tom Shippey, John Garth, Mark J.P. Wolf, Kristine Larsen, Andrew Higgins, Allan Turner, Gergely Nagy, Ren&eacute;e Vink, and a dozen other scholars, discuss not only Tolkien&rsquo;s theoretical concepts as well as his literary work but also explore the relationship between Tolkien&rsquo;s approach with that of other &lsquo;literary world-builders&rsquo; whose imaginary worlds have attracted readers and scholars alike.</p>