Michael D. C. Drout published The J. R. R. Tolkien Encyclopedia through Routledge in 2006. He assembled a team of 127 scholars from many countries to fill the 720-page volume with content about the author's life and works.
Taylor & Francis acquired Routledge while the encyclopedia was still being produced, which caused severe disruptions to the publishing process. This corporate takeover led to the cancellation of all planned illustrations before publication and resulted in numerous errors throughout the book.
Reviewers found that the quality varied wildly between entries within The J. R. R. Tolkien Encyclopedia. Kelley Wickham-Crowley stated that some essays were masterful while others felt pedestrian and underdeveloped, and Jennifer Goodfellow observed that some articles provided only short summaries while others offered deep analysis.
The J. R. R. Tolkien Encyclopedia covers adaptations for cinema, stage, and television alongside discussions of art and illustrations. It also delves into theological concepts, philosophical ideas, contemporary history influencing the author, real languages, invented tongues, and literary sources.
Co-editors Douglas A. Anderson, Verlyn Flieger, Marjorie Burns, and Tom Shippey joined Michael D. C. Drout on this massive project. Their goal was to create a resource appealing to both casual readers and serious academics through collaborative effort.